Michael addition curing chemistries for sulfur-containing polymer compositions

ABSTRACT

The use of Michael addition curing chemistries in compositions comprising sulfur-containing polymers such as polythioethers and polysulfides useful in aerospace sealant applications are disclosed. Sulfur-containing adducts comprising terminal Michael acceptor groups are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 13/529,237 filed on Jun. 21, 2012, now allowed,which is incorporated by reference in its entirety.

FIELD

The present disclosure relates to the use of Michael addition curingchemistries in compositions comprising sulfur-containing polymers, suchas polythioethers and polysulfides, useful in aerospace sealantapplications. The disclosure also relates to sulfur-containing adductshaving terminal Michael acceptor groups and compositions thereof.

BACKGROUND

Sealants useful in aerospace and other applications must satisfydemanding mechanical, chemical, and environmental requirements. Thesealants can be applied to a variety of surfaces including metalsurfaces, primer coatings, intermediate coatings, finished coatings, andaged coatings. In sealants such as those described in U.S. Pat. No.6,123,179 an amine catalyst is used to provide a cured product. Suchsystems typically cure in over two hours and although exhibitingacceptable fuel resistance and thermal resistance for many applications,a faster curing rate and improved performance is desirable.

SUMMARY

Michael addition curing chemistries are often used in acrylic-basedpolymer systems and as disclosed in U.S. Pat. No. 3,138,573 have beenadapted for use in polysulfide compositions. Application of Michaeladdition curing chemistries to sulfur-containing polymers not onlyresults in cured sealants with faster cure rates and enhancedperformance including fuel resistance and thermal resistance, but alsoprovides a sealant with improved physical properties, such aselongation.

In a first aspect, polythioether adducts comprising at least twoterminal Michael acceptor groups are provided.

In a second aspect, compositions are provided comprising a polythioetherpolymer comprising at least two terminal groups reactive with Michaelacceptor groups; and a compound having at least two Michael acceptorgroups.

In a third aspect, compositions are provided comprising a polythioetheradduct provided by the present disclosure and a curing agent comprisingat least two terminal groups that are reactive with Michael acceptorgroups.

In a fourth aspect, compositions are provided comprising (a) thesulfur-containing adduct provided by the present disclosure; (b) asulfur-containing polymer comprising at least two terminal groupsreactive with Michael acceptor groups; and (c) a monomeric compoundhaving at least two Michael acceptor groups.

In a fifth aspect, hydroxyl-terminated sulfur-containing adducts areprovided comprising the reaction products of reactants comprising (a) asulfur-containing Michael acceptor adduct provided by the presentdisclosure; and (b) a compound having a hydroxyl group and a group thatis reactive with the terminal groups of the sulfur-containing Michaelacceptor adduct.

In a sixth aspect, compositions are provided comprising (a) ahydroxyl-terminated sulfur-containing adduct provided by the presentdisclosure; and (b) a polyisocyanate curing agent.

In a seventh aspect, amine-terminated sulfur-containing adducts areprovided comprising the reaction products of reactants comprising (a) asulfur-containing Michael acceptor adduct provided by the presentdisclosure; and (b) a compound having a amine group and a group that isreactive with the terminal groups of the sulfur-containing Michaelacceptor adduct.

In an eighth aspect, compositions are provided comprising (a) anamine-terminated sulfur-containing adduct provided by the presentdisclosure; and (b) a polyisocyanate curing agent.

In a ninth aspect, cured sealants comprising a composition provided bythe present disclosure are provided.

In a tenth aspect, apertures sealed with a composition provided bypresent disclosure are provided.

In an eleventh aspect, methods of sealing an aperture are providedcomprising (a) applying a composition provided by the present disclosureformulated as a sealant to at least one surface defining an aperture;(b) assembling the surfaces defining the aperture; and (c) curing thecomposition to provide a sealed aperture.

DETAILED DESCRIPTION Definitions

For purposes of the following description, it is to be understood thatembodiments provided by the present disclosure may assume variousalternative variations and step sequences, except where expresslyspecified to the contrary. Moreover, other than in the examples, orwhere otherwise indicated, all numbers expressing, for example,quantities of ingredients used in the specification and claims are to beunderstood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired properties to beobtained. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges encompassed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of about 1 and the recited maximumvalue of about 10, that is, having a minimum value equal to or greaterthan about 1 and a maximum value of equal to or less than about 10.Also, in this application, the use of “or” means “and/or” unlessspecifically stated otherwise, even though “and/or” may be explicitlyused in certain instances.

A dash (“-”) that is not between two letters or symbols is used toindicate a point of bonding for a substituent or between two atoms. Forexample, —CONH₂ is bonded to another chemical moiety through the carbonatom.

“Alkanediyl” refers to a diradical of a saturated, branched orstraight-chain, acyclic hydrocarbon group, having, for example, from 1to 18 carbon atoms (C₁₋₁₈), from 1 to 14 carbon atoms (C₁₋₁₄), from 1 to6 carbon atoms (C₁₋₆), from 1 to 4 carbon atoms (C₁₋₄), or from 1 to 3hydrocarbon atoms (C₁₋₃). It will be appreciated that a branchedalkanediyl has a minimum of three carbon atoms. In certain embodiments,the alkanediyl is C₂₋₁₄ alkanediyl, C₂₋₁₀ alkanediyl, C₂₋₈ alkanediyl,C₂₋₆ alkanediyl, C₂₋₄ alkanediyl, and in certain embodiments, C₂₋₃alkanediyl. Examples of alkanediyl groups include methane-diyl (—CH₂—),ethane-1,2-diyl (—CH₂CH₂—), propane-1,3-diyl and iso-propane-1,2-diyl(e.g., —CH₂CH₂CH₂— and —CH(CH₃)CH₂—), butane-1,4-diyl (—CH₂CH₂CH₂CH₂—),pentane-1,5-diyl (—CH₂CH₂CH₂CH₂CH₂—), hexane-1,6-diyl(—CH₂CH₂CH₂CH₂CH₂CH₂—), heptane-1,7-diyl, octane-1,8-diyl,nonane-1,9-diyl, decane-1,10-diyl, dodecane-1,12-diyl, and the like.

“Alkanecycloalkane” refers to a saturated hydrocarbon group having oneor more cycloalkyl and/or cycloalkanediyl groups and one or more alkyland/or alkanediyl groups, where cycloalkyl, cycloalkanediyl, alkyl, andalkanediyl are defined herein. In certain embodiments, each cycloalkyland/or cycloalkanediyl group(s) is C₃₋₆, C₅₋₆, and in certainembodiments, cyclohexyl or cyclohexanediyl. In certain embodiments, eachalkyl and/or alkanediyl group(s) is C₁₋₆, C₁₋₄, C₁₋₃, and in certainembodiments, methyl, methanediyl, ethyl, or ethane-1,2-diyl. In certainembodiments, the alkanecycloalkane group is C₄₋₁₈ alkanecycloalkane,C₄₋₁₆ alkanecycloalkane, C₄₋₁₂ alkanecycloalkane, C₄₋₈alkanecycloalkane, C₆₋₁₂ alkanecycloalkane, C₆₋₁₀ alkanecycloalkane, andin certain embodiments, C₆₋₉ alkanecycloalkane. Examples ofalkanecycloalkane groups include 1,1,3,3-tetramethylcyclohexane andcyclohexylmethane.

“Alkanecycloalkanediyl” refers to a diradical of an alkanecycloalkanegroup. In certain embodiments, the alkanecycloalkanediyl group is C₄₋₁₈alkanecycloalkanediyl, C₄₋₁₆ alkanecycloalkanediyl, C₄₋₁₂alkanecycloalkanediyl, C₄₋₈ alkanecycloalkanediyl, C₆₋₁₂alkanecycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, and in certainembodiments, C₆₋₉ alkanecycloalkanediyl. Examples ofalkanecycloalkanediyl groups include1,1,3,3-tetramethylcyclohexane-1,5-diyl and cyclohexylmethane-4,4′-diyl.

“Alkanearene” refers to a hydrocarbon group having one or more aryland/or arenediyl groups and one or more alkyl and/or alkanediyl groups,where aryl, arenediyl, alkyl, and alkanediyl are defined here. Incertain embodiments, each aryl and/or arenediyl group(s) is C₆₋₁₂,C₆₋₁₀, and in certain embodiments, phenyl or benzenediyl. In certainembodiments, each alkyl and/or alkanediyl group(s) is C₁₋₆, C₁₋₄, C₁₋₃,and in certain embodiments, methyl, methanediyl, ethyl, orethane-1,2-diyl. In certain embodiments, the alkanearene group is C₄₋₁₈alkanearene, C₄₋₁₆ alkanearene, C₄₋₁₂ alkanearene, C₄₋₈ alkanearene,C₆₋₁₂ alkanearene, C₆₋₁₀ alkanearene, and in certain embodiments, C₆₋₉alkanearene. Examples of alkanearene groups include diphenyl methane.

“Alkanearenediyl” refers to a diradical of an alkanearene group. Incertain embodiments, the alkanearenediyl group is C₄₋₁₈ alkanearenediyl,C₄₋₁₆ alkanearenediyl, C₄₋₁₂ alkanearenediyl, C₄₋₈ alkanearenediyl,C₆₋₁₂ alkanearenediyl, C₆₋₁₀ alkanearenediyl, and in certainembodiments, C₆₋₉ alkanearenediyl. Examples of alkanearenediyl groupsinclude diphenyl methane-4,4′-diyl.

“Alkenyl” group refers to a group (R)₂C═C(R)₂. In certain embodiments,an alkenyl group has the structure —RC═C(R)₂ where the alkenyl group isa terminal group and is bonded to a larger molecule. In suchembodiments, each R may be selected from, for example, hydrogen and C₁₋₃alkyl. In certain embodiments, each R is hydrogen and an alkenyl grouphas the structure —CH═CH₂.

“Alkoxy” refers to a —OR group where R is alkyl as defined herein.Examples of alkoxy groups include methoxy, ethoxy, n-propoxy,isopropoxy, and n-butoxy. In certain embodiments, the alkoxy group isC₁₋₈ alkoxy, C₁₋₆ alkoxy, C₁₋₄ alkoxy, and in certain embodiments, C₁₋₃alkoxy.

“Alkyl” refers to a monoradical of a saturated, branched orstraight-chain, acyclic hydrocarbon group having, for example, from 1 to20 carbon atoms, from 1 to 10 carbon atoms, from 1 to 6 carbon atoms,from 1 to 4 carbon atoms, or from 1 to 3 carbon atoms. It will beappreciated that a branched alkyl has a minimum of three carbon atoms.In certain embodiments, the alkyl group is C₂₋₆ alkyl, C₂₋₄ alkyl, andin certain embodiments, C₂₋₃ alkyl. Examples of alkyl groups includemethyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl,n-hexyl, n-decyl, tetradecyl, and the like. In certain embodiments, thealkyl group is C₂₋₆ alkyl, C₂₋₄ alkyl, and in certain embodiments, C₂₋₃alkyl. It will be appreciated that a branched alkyl has at least threecarbon atoms.

“Arenediyl” refers to diradical monocyclic or polycyclic aromatic group.Examples of arenediyl groups include benzene-diyl and naphthalene-diyl.In certain embodiments, the arenediyl group is C₆₋₁₂ arenediyl, C₆₋₁₀arenediyl, C₆₋₉ arenediyl, and in certain embodiments, benzene-diyl.

“Cycloalkanediyl” refers to a diradical saturated monocyclic orpolycyclic hydrocarbon group. In certain embodiments, thecycloalkanediyl group is C₃₋₁₂ cycloalkanediyl, C₃₋₈ cycloalkanediyl,C₃₋₆ cycloalkanediyl, and in certain embodiments, C₅₋₆ cycloalkanediyl.Examples of cycloalkanediyl groups include cyclohexane-1,4-diyl,cyclohexane-1,3-diyl, and cyclohexane-1,2-diyl.

“Cycloalkyl” refers to a saturated monocyclic or polycyclic hydrocarbonmonoradical group. In certain embodiments, the cycloalkyl group is C₃₋₁₂cycloalkyl, C₃₋₈ cycloalkyl, C₃₋₆ cycloalkyl, and in certainembodiments, C₅₋₆ cycloalkyl.

“Heteroalkanediyl” refers to an alkanediyl group in which one or more ofthe carbon atoms are replaced with a heteroatom, such as N, O, S, or P.In certain embodiments of heteroalkanediyl, the heteroatom is selectedfrom N and O.

“Heterocycloalkanediyl” refers to a cycloalkanediyl group in which oneor more of the carbon atoms are replaced with a heteroatom, such as N,O, S, or P. In certain embodiments of heterocycloalkanediyl, theheteroatom is selected from N and O.

“Heteroarenediyl” refers to an arenediyl group in which one or more ofthe carbon atoms are replaced with a heteroatom, such as N, O, S, or P.In certain embodiments of heteroarenediyl, the heteroatom is selectedfrom N and O.

“Heterocycloalkanediyl” refers to a cycloalkanediyl group in which oneor more of the carbon atoms are replaced with a heteroatom, such as N,O, S, or P. In certain embodiments of heterocycloalkanediyl, theheteroatom is selected from N and O.

A “Michael acceptor” refers to an activated alkene, such as an alkenylgroup proximate to an electron-withdrawing group such as an ketone,nitro, halo, nitrile, carbonyl, or nitro group. Michael acceptors arewell known in the art. A “Michael acceptor group” refers to an activatedalkenyl group and an electron-withdrawing group. In certain embodiments,a Michael acceptor group is selected from a vinyl ketone, a vinylsulfone, a quinone, an enamine, a ketimine, oxazolidine, and anacrylate. Other examples of Michael acceptors are disclosed in Mather etal., Prog. Polym. Sci. 2006, 31, 487-531, and include acrylate esters,acrylonitrile, acrylamides, maleimides, alkyl methacrylates,cyanoacrylates. Other Michael acceptors include vinyl ketones,α,β-unsaturated aldehydes, vinyl phosphonates, acrylonitrile, vinylpyridines, certain azo compounds, β-keto acetylenes and acetyleneesters. In certain embodiments, a Michael acceptor group is derived froma vinyl ketone and has the structure of Formula (2):

—S(O)₂—C(R)₂═CH₂  (2)

where each R is independently selected from hydrogen, fluorine, and C₁₋₃alkyl. In certain embodiments, each R is hydrogen. In certainembodiments, a Michael acceptor or Michael acceptor group does notencompass acrylates. A “Michael acceptor compound” refers to a compoundcomprising at least one Michael acceptor. In certain embodiments, aMichael acceptor compound is divinyl sulfone, and a Michael acceptorgroup is vinylsulfonyl (—S(O)₂—CH₂═CH₂).

As used herein, “polymer” refers to oligomers, homopolymers, andcopolymers. Unless stated otherwise, molecular weights are numberaverage molecular weights for polymeric materials indicated as “Mn” asdetermined, for example, by gel permeation chromatography using apolystyrene standard in an art-recognized manner.

“Substituted” refers to a group in which one or more hydrogen atoms areeach independently replaced with the same or different substituent(s).In certain embodiments, the substituent is selected from halogen,—S(O)₂OH, —S(O)₂, —SH, —SR where R is C₁₋₆ alkyl, —COOH, —NO₂, —NR₂where each R is independently selected from hydrogen and C₁₋₃ alkyl,—CN, ═O, C₁₋₆ alkyl, —CF₃, —OH, phenyl, C₂₋₆ heteroalkyl, C₅₋₆heteroaryl, C₁₋₆ alkoxy, and —COR where R is C₁₋₆ alkyl. In certainembodiments, the substituent is chosen from —OH, —NH₂, and C₁₋₃ alkyl.

Reference is now made to certain embodiments of sulfur-containingadducts having terminal Michael acceptor groups, polymers, compositions,and methods. The disclosed embodiments are not intended to be limitingof the claims. To the contrary, the claims are intended to cover allalternatives, modifications, and equivalents.

Sulfur-Containing Adducts

Sulfur-containing adducts provided by the present disclosure compriseterminal Michael acceptor groups. Sulfur-containing polymers usefulherein include, for example, polythioethers, polysulfides, andcombinations thereof. Examples of suitable polythioethers are disclosedin U.S. Pat. No. 6,123,179. Examples of suitable polysulfides aredisclosed in U.S. Pat. No. 4,623,711. In certain embodiments, asulfur-containing adduct may be difunctional, and in certainembodiments, may have a functionality greater than 2 such as 3, 4, 5, or6. A sulfur-containing adduct may comprise a mixture ofsulfur-containing adducts having different functionalities characterizedby an average functionality from 2.05 to 6, from 2.1 to 4, from 2.1 to3, from 2.2 to 2.8, and in certain embodiments, from 2.4 to 2.6.Sulfur-containing adducts have at least two terminal Michael acceptorgroups, and in certain embodiments have two Michael acceptor groups, 3,4, 5, or 6 Michael acceptor groups. A sulfur-containing adduct maycomprise a combination of adducts having different numbers of terminalMichael acceptor groups characterized, for example, by an averageMichael acceptor functionality of from 2.05 to 6, from 2.1 to 4, from2.1 to 3, from 2.2 to 2.8, and in certain embodiments, from 2.4 to 2.6.

In certain embodiments, a sulfur-containing adduct comprises apolythioether adduct characterized by a polythioether having at leasttwo terminal Michael acceptor groups.

In certain embodiments, a sulfur-containing adduct comprises apolythioether adduct comprising:

(a) a backbone comprising the structure of Formula (1):

—R¹-[—S—(CH₂)₂—O—[—R²—O—]_(m)(CH₂)₂—S—R¹]_(n)—  (1)

where (i) each R¹ is independently selected from a C₂₋₁₀ n-alkanediylgroup, a C₃₋₆ branched alkanediyl group, a C₆₋₈ cycloalkanediyl group, aC₆₋₁₀ alkanecycloalkanediyl group, a heterocyclic group, a—[(—CHR³—)_(p)—X—]_(q)—(CHR³)_(r)— group, wherein each R³ isindependently selected from hydrogen and methyl; (ii) each R² isindependently selected from a C₂₋₁₀ n-alkanediyl group, a C₃₋₆ branchedalkanediyl group, a C₆₋₈ cycloalkanediyl group, a C₆₋₁₄alkanecycloalkanediyl group, a heterocyclic group, and a—[(CH₂—)_(p)—X-]_(q)—(CH₂)_(r)— group; (iii) each X is independentlyselected from O, S, and a —NR⁶— group, in which R⁶ is selected from Hand a methyl group; (iv) m ranges from 0 to 50; (v) n is an integerranging from 1 to 60; (vi) p is an integer ranging from 2 to 6; (vii) qis an integer ranging from 1 to 5; and (viii) r is an integer rangingfrom 2 to 10; and (b) at least two terminal Michael acceptor groups.

In certain embodiments of a compound of Formula (1), R¹ is—[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)— wherein each X is independentlyselected from —O— and —S—. In certain embodiments wherein R¹ is—[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—, each X is —O— and in certainembodiments, each X is —S—.

In certain embodiments of a compound of Formula (1), R¹ is—[—(CH₂)_(s)—X-]_(q)—(CH₂)_(r)— wherein each X is independently selectedfrom —O— and —S—. In certain embodiments wherein R¹ is—[—(CH₂)_(s)—X-]_(q)—(CH₂)_(r)—, each X is —O— and in certainembodiments, each X is —S—.

In certain embodiments, R¹ in Formula (3a) is—[(—CH₂—)_(p)—X-]_(q)—(CH₂)_(r)—, where p is 2, X is O, q is 2, r is 2,R² is ethanediyl, m is 2, and n is 9.

Michael acceptor groups are well known in the art. In certainembodiments, a Michael acceptor group comprises an activated alkene,such as an alkenyl group proximate to an electron-withdrawing group suchas an enone, nitro, halo, nitrile, carbonyl, or nitro group. In certainembodiments, a Michael acceptor group is selected from a vinyl ketone, avinyl sulfone, a quinone, an enamine, a ketimine, an aldimine, and anoxazolidine. In certain embodiments, each of the Michael acceptor groupsmay be the same and in certain embodiments, at least some of the Michaelacceptor groups are different.

In certain embodiments, a Michael acceptor group is derived from a vinylsulfone and has the structure of Formula (2):

—CH₂—C(R⁴)₂—S(O)₂—C(R⁴)₂═CH₂  (2)

wherein each R⁴ is independently selected from hydrogen and C₁₋₃ alkyl.In certain embodiments of Formula (2), each R⁴ is hydrogen.

In certain embodiments where the sulfur-containing adduct comprises apolythioether adduct, the polythioether adduct is selected from apolythioether adduct of Formula (3), a polythioether adduct of Formula(3a), and a combination thereof:

R⁶—S—R¹-[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—R⁶  (3)

{R⁶—S—R —[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′-}_(z)B  (3a)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NHR—,            wherein R is selected from hydrogen and methyl;    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60;    -   p is an integer from 2 to 6;    -   B represents a core of a z-valent, vinyl-terminated        polyfunctionalizing agent B(—V)_(z) wherein:        -   z is an integer from 3 to 6; and        -   each V is a group comprising a terminal vinyl group; and    -   each —V′— is derived from the reaction of —V with a thiol; and    -   each R⁶ is independently a moiety comprising a terminal Michael        acceptor group.

In certain embodiments of Formula (3) and in Formula (3a), R¹ is—[(—CH₂—)_(p)—X-]_(q)—(CH₂)_(r)—, where p is 2, X is —O—, q is 2, r is2, R² is ethanediyl, m is 2, and n is 9.

In certain embodiments of Formula (3) and Formula (3a), R¹ is selectedfrom C₂₋₆ alkanediyl and —[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—.

In certain embodiments of Formula (3) and Formula (3a), R¹ is—[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—, and in certain embodiments X is —O—and in certain embodiments, X is —S—.

In certain embodiments of Formula (3) and Formula (3a), where R¹ is—[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—, p is 2, r is 2, q is 1, and X is —S—;in certain embodiments, wherein p is 2, q is 2, r is 2, and X is —O—;and in certain embodiments, p is 2, r is 2, q is 1, and X is —O—.

In certain embodiments of Formula (3) and Formula (3a), where R¹ is—[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—, each R³ is hydrogen, and in certainembodiments, at least one R³ is methyl.

In certain embodiment of adducts of Formula (3) and Formula (3a), eachR¹ is the same, and in certain embodiments, at least one R¹ isdifferent.

In certain embodiments of adducts of Formula (3) and Formula (3a), eachR⁶ is independently selected from a vinyl ketone, a vinyl sulfone, aquinone, an enamine, a ketimine, an aldimine, and an oxazolidine. Incertain embodiments, each of the Michael acceptor groups may be the sameand in certain embodiments, at least some of the Michael acceptor groupsare different.

In certain embodiments of adducts of Formula (3) and Formula (3a), eachR⁶ is independently derived from a vinyl sulfone and has the structureof Formula (2):

—CH₂—C(R⁴)₂—S(O)₂—C(R⁴)₂═CH₂  (2)

wherein each R⁴ is independently selected from hydrogen and C₁₋₃ alkyl.In certain embodiments of compounds of Formula (3) and Formula (3a)where each R⁶ is a moiety of Formula (2), each R⁴ is hydrogen.

In certain embodiments, a sulfur-containing adduct comprises apolysulfide adduct comprising at least two terminal Michael acceptorgroups.

As used herein, the term polysulfide refers to a polymer that containsone or more disulfide linkages, i.e., —[S—S]— linkages, in the polymerbackbone and/or in pendant positions on the polymer chain. In certainembodiments, the polysulfide polymer will have two or more sulfur-sulfurlinkages. Suitable polysulfides are commercially available, for example,from Akzo Nobel and Toray Fine Chemicals under the names Thiokol-LP andThioplast®. Thioplast® products are available in a wide range ofmolecular weights ranging, for example, from less than 1,100 to over8,000, with molecular weight being the average molecular weight in gramsper mole. In some cases, the polysulfide has a number average molecularweight of 1,000 to 4,000. The crosslink density of these products alsovaries, depending on the amount of crosslinking agent used. The —SHcontent, i.e., thiol or mercaptan content, of these products can alsovary. The mercaptan content and molecular weight of the polysulfide canaffect the cure speed of the polymer, with cure speed increasing withmolecular weight.

In certain embodiments provided by the present disclosure, a polysulfidecomposition comprises: (a) from 90 mole percent to 25 mole percent ofmercaptan terminated disulfide polymer of the Formula HS(RSS)_(m)R—SH;and (b) from 10 mole percent to 75 mole percent of diethyl formalmercaptan terminated polysulfide polymer of the Formula HS(RSS)_(n)R—SH,wherein R is —C₂H₄—O—CH₂—O—C₂H₄—; R is a divalent member selected fromalkyl of from 2 to 12 carbon atoms, alkyl thioether of from 4 to 20carbon atoms, alkyl ether of from 4 to 20 carbon atoms and one oxygenatom, alkyl ether of from 4 to 20 carbon atoms and from 2 to 4 oxygenatoms each of which is separated from the other by at least 2 carbonatoms, alicyclic of from 6 to 12 carbon atoms, and aromatic lower alkyl;and the value of m and n is such that the diethyl formal mercaptanterminated polysulfide polymer and the mercaptan terminated disulfidepolymer have an average molecular weight of from 1,000 Daltons to 4,000Daltons, such as 1,000 Daltons to 2,500 Daltons. Such polymeric mixturesare described in U.S. Pat. No. 4,623,711 at col. 4, line 18 to col. 8,line 35, the cited portion of which is incorporated by reference herein.In some cases, R in the above formula is —CH₂—CH₂—; —C₂H₄—O—C₂H₄—;—C₂H₄—S—C₂H₄—; —C₂H₄—O—C₂H₄—O—C₂H₄—; or —CH₂—C₆H₄—CH₂—.

In certain embodiments, a sulfur-containing adduct comprises apolythioether adduct comprising at least two terminal Michael acceptorgroups, a polysulfide adduct comprising at least two terminal Michaelacceptor groups, or a combination thereof.

In certain embodiments, sulfur-containing Michael acceptor adductsprovided by the present disclosure comprise the reaction products ofreactants comprising: (a) a sulfur-containing polymer; and (b) acompound having a Michael acceptor group and a group that is reactivewith a terminal group of the sulfur-containing polymer.

In certain embodiments, the sulfur-containing polymer is selected from apolythioether and a polysulfide, and a combination thereof. In certainembodiments a sulfur-containing polymer comprises a polythioether, andin certain embodiments, a sulfur-containing polymer comprises apolysulfide. A sulfur-containing polymer may comprise a mixture ofdifferent polythioethers and/or polysulfides, and the polythioethersand/or polysulfides may have the same or different functionality. Incertain embodiments, a sulfur-containing polymer has an averagefunctionality from 2 to 6, from 2 to 4, from 2 to 3, and in certainembodiments, from 2.05 to 2.5. For example, a sulfur-containing polymercan be selected from a difunctional sulfur-containing polymer, atrifunctional sulfur-containing polymer, and a combination thereof.

In certain embodiments, a sulfur-containing polymer is terminated with agroup that is reactive with the terminal reactive group of the compound(b). In certain embodiments, the compound having a Michael acceptorgroup has two Michael acceptor groups, and the terminal groups of thesulfur-containing polymer are reactive with Michael acceptor groups suchas a thiol group. A sulfur-containing polymer may comprise terminalthiol groups, terminal alkenyl groups, or terminal epoxy groups.

In certain embodiments, a sulfur-containing polymer is thiol-terminated.Examples of thiol-functional polythioethers are disclosed, for examplein U.S. Pat. No. 6,172,179. In certain embodiments, a thiol-functionalpolythioether comprises Permapol® P3.1E, available from PRC-DeSotoInternational Inc., Sylmar, Calif.

In certain embodiments, a sulfur-containing polymer comprises apolythioether comprising:

(a) a backbone comprising the structure of Formula (1):

—R¹-[—S—(CH₂)₂—O—[—R²—O-]_(m)(CH₂)₂—S—R¹]_(n)—  (1)

wherein:

-   -   (i) each R¹ is independently selected from a C₂₋₁₀ n-alkanediyl        group, a C₃₋₆ branched alkanediyl group, a C₆₋₈ cycloalkanediyl        group, a C₆₋₁₀ alkanecycloalkanediyl group, a heterocyclic        group, a —[(—CHR³—)_(p)—X-]_(q)—(CHR³—)_(r)— group, wherein each        R³ is selected from hydrogen and methyl;    -   (ii) each R² is independently selected from a C₂₋₁₀ n-alkanediyl        group, a C₃₋₆ branched alkanediyl group, a C₆₋₈ cycloalkanediyl        group, a C₆₋₁₄ alkanecycloalkanediyl group, a heterocyclic        group, and a —[(—CH₂—)_(p)—X-]_(q)—(CH₂)_(r)— group;    -   (iii) each X is independently selected from O, S, and a —NR⁶—        group, in which R⁶ is selected from H and a methyl group;    -   (iv) m ranges from 0 to 50;    -   (v) n is an integer ranging from 1 to 60;    -   (vi) p is an integer ranging from 2 to 6;    -   (vii) q is an integer ranging from 1 to 5; and    -   (viii) r is an integer ranging from 2 to 10.

In certain embodiments, a sulfur-containing polymer comprises apolythioether selected from a polythioether of Formula (4), apolythioether of Formula (4a), and a combination thereof:

HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (4)

{HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′-}_(z)B  (4a)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NHR—,            wherein R is selected from hydrogen and methyl;    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined as for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60;    -   p is an integer from 2 to 6;    -   B represents a core of a z-valent, vinyl-terminated        polyfunctionalizing agent B(—V)_(z) wherein:        -   z is an integer from 3 to 6; and        -   each V is a group comprising a terminal vinyl group; and    -   each —V′— is derived from the reaction of —V with a thiol.

In certain embodiments, Formula (4) and in Formula (4a), R¹ is—[(—CH₂—)_(p)—X-]_(q)—(CH₂)_(r), where p is 2, X is —O—, q is 2, r is 2,R² is ethanediyl, m is 2, and n is 9.

In certain embodiments of Formula (4) and Formula (4a), R¹ is selectedfrom C₂₋₆ alkanediyl and —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—.

In certain embodiments of Formula (4) and Formula (4a), R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, and in certain embodiments X is —O—and in certain embodiments, X is —S—.

In certain embodiments of Formula (4) and Formula (4a), where R¹ is—[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—, p is 2, r is 2, q is 1, and X is —S—;in certain embodiments, wherein p is 2, q is 2, r is 2, and X is —O—;and in certain embodiments, p is 2, r is 2, q is 1, and X is —O—.

In certain embodiments of Formula (4) and Formula (4a), where R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, each R³ is hydrogen, and in certainembodiments, at least one R³ is methyl.

In certain embodiments of Formula (4) and Formula (4a), each R¹ is thesame, and in certain embodiments, at least one R¹ is different.

Various methods can be used to prepare such polythioethers. Examples ofsuitable thiol-functional polythioethers, and methods for theirproduction, are described in U.S. Pat. No. 6,172,179 at col. 2, line 29to col. 4, line 22; col. 6, line 39 to col. 10, line 50; and col. 11,lines 65 to col. 12, line 22, the cited portions of which areincorporated herein by reference. Such thiol-functional polythioethersmay be difunctional, that is, linear polymers having two thiol terminalgroups, or polyfunctional, that is, branched polymers have three or morethiol terminal groups. Suitable thiol-functional polythioethers arecommercially available, for example, as Permapol® P3.1E, from PRC-DeSotoInternational Inc., Sylmar, Calif.

Suitable thiol-functional polythioethers may be produced by reacting adivinyl ether or mixtures of divinyl ethers with an excess of dithiol ora mixtures of dithiols. For example, dithiols suitable for use inpreparing thiol-functional polythioethers include those having Formula(5), other dithiols disclosed herein, or combinations of any of thedithiols disclosed herein.

In certain embodiments, a dithiol has the structure of Formula (5):

HS—R¹—SH  (5)

wherein:

-   -   R¹ is selected from C₂₋₆ alkanediyl, C₆₋₈ cycloalkanediyl, C₆₋₁₀        alkanecycloalkanediyl, C₅₋₈ heterocycloalkanediyl, and        —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—;    -   wherein:        -   each R³ is independently selected from hydrogen and methyl;        -   each X is independently selected from —O—, —S—, and —NR—            wherein R is selected from hydrogen and methyl;        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5; and        -   r is an integer from 2 to 10.

In certain embodiments of a dithiol of Formula (5), R¹ is—[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—.

In certain embodiments of a compound of Formula (5), X is selected from—O— and —S—, and thus —[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)— in Formula (5)is —[(—CHR³—)—O-]_(q)—(CHR³)_(r)— or —[(CHR³₂—)_(p)—S-]_(q)—(CHR³)_(r)—. In certain embodiments, p and r are equal,such as where p and r are both two.

In certain embodiments of a dithiol of Formula (5), R¹ is selected fromC₂₋₆ alkanediyl and —[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—.

In certain embodiments, R¹ is —[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—, and incertain embodiments X is —O—, and in certain embodiments, X is —S—.

In certain embodiments where R¹ is —[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—, pis 2, r is 2, q is 1, and X is —S—; in certain embodiments, wherein p is2, q is 2, r is 2, and X is —O—; and in certain embodiments, p is 2, ris 2, q is 1, and X is —O—.

In certain embodiments where R¹ is —[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—,each R³ is hydrogen, and in certain embodiments, at least one R³ ismethyl.

Examples of suitable dithiols include, for example, 1,2-ethanedithiol,1,2-propanedithiol, 1,3-propanedithiol, 1,3-butanedithiol,1,4-butanedithiol, 2,3-butanedithiol, 1,3-pentanedithiol,1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane,dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT),dimercaptodiethylsulfide, methyl-substituted dimercaptodiethylsulfide,dimethyl-substituted dimercaptodiethylsulfide, dimercaptodioxaoctane,1,5-dimercapto-3-oxapentane, and a combination of any of the foregoing.A polythiol may have one or more pendant groups selected from a lower(e.g., C₁₋₆) alkyl group, a lower alkoxy group, and a hydroxyl group.Suitable alkyl pendant groups include, for example, C₁₋₆ linear alkyl,C₃₋₆ branched alkyl, cyclopentyl, and cyclohexyl.

Other examples of suitable dithiols include dimercaptodiethylsulfide(DMDS) (in Formula (5), R¹ is —[(—CH₂—)_(p)—X-]_(q)—(CH₂)_(r)—, whereinp is 2, r is 2, q is 1, and X is —S—); dimercaptodioxaoctane (DMDO) (inFormula (5), R¹ is —[(—CH₂—)_(p)—X-]_(q)—(CH₂)_(r)—, wherein p is 2, qis 2, r is 2, and X is —O—); and 1,5-dimercapto-3-oxapentane (in Formula(5), R¹ is —[(—CH₂—)_(p)—X-]_(q)—(CH₂)_(r)—, wherein p is 2, r is 2, qis 1, and X is —O—). It is also possible to use dithiols that includeboth heteroatoms in the carbon backbone and pendant alkyl groups, suchas methyl groups. Such compounds include, for example,methyl-substituted DMDS, such as HS—CH₂CH(CH₃)—S—CH₂CH₂—SH,HS—CH(CH₃)CH₂—S—CH₂CH₂—SH and dimethyl substituted DMDS, such asHS—CH₂CH(CH₃)—S—CHCH₃CH₂—SH and HS—CH(CH₃)CH₂—S—CH₂CH(CH₃)—SH.

Suitable divinyl ethers for preparing polythioethers and polythioetheradducts include, for example, divinyl ethers of Formula (6):

CH₂═CH—O—(—R²—O—)_(m)—CH═CH₂  (6)

where R² in Formula (6) is selected from a C₂₋₆ n-alkanediyl group, aC₃₋₆ branched alkanediyl group, a C₆₋₈ cycloalkanediyl group, a C₆₋₁₀alkanecycloalkanediyl group, and —[(—CH₂—)_(p)—O-]_(q)—(—CH₂—)_(r)—,where p is an integer ranging from 2 to 6, q is an integer from 1 to 5,and r is an integer from 2 to 10. In certain embodiments of a divinylether of Formula (6), R² is a C₂₋₆ n-alkanediyl group, a C₃₋₆ branchedalkanediyl group, a C₆₋₈ cycloalkanediyl group, a C₆₋₁₀alkanecycloalkanediyl group, and in certain embodiments,—[(—CH₂—)_(p)—O-]_(q)—(—CH₂—)_(r)—.

Suitable divinyl ethers include, for example, compounds having at leastone oxyalkanediyl group, such as from 1 to 4 oxyalkanediyl groups, i.e.,compounds in which m in Formula (6) is an integer ranging from 1 to 4.In certain embodiments, m in Formula (6) is an integer ranging from 2 to4. It is also possible to employ commercially available divinyl ethermixtures that are characterized by a non-integral average value for thenumber of oxyalkanediyl units per molecule. Thus, m in Formula (6) canalso take on rational number values ranging from 0 to 10.0, such as from1.0 to 10.0, from 1.0 to 4.0, or from 2.0 to 4.0.

Examples of suitable divinyl ethers include, for example, divinyl ether,ethylene glycol divinyl ether (EG-DVE) (R² in Formula (6) is ethanediyland m is 1), butanediol divinyl ether (BD-DVE) (R² in Formula (6) isbutanediyl and m is 1), hexanediol divinyl ether (HD-DVE) (R² in Formula(6) is hexanediyl and m is 1), diethylene glycol divinyl ether (DEG-DVE)(R² in Formula (4) is ethanediyl and m is 2), triethylene glycol divinylether (R² in Formula (14) is ethanediyl and m is 3), tetraethyleneglycol divinyl ether (R² in Formula (6) is ethanediyl and m is 4),cyclohexanedimethanol divinyl ether, polytetrahydrofuryl divinyl ether;trivinyl ether monomers, such as trimethylolpropane trivinyl ether;tetrafunctional ether monomers, such as pentaerythritol tetravinylether; and combinations of two or more such polyvinyl ether monomers. Apolyvinyl ether may have one or more pendant groups selected from alkylgroups, hydroxyl groups, alkoxy groups, and amine groups.

In certain embodiments, divinyl ethers in which R² in Formula (6) isC₃₋₆ branched alkanediyl may be prepared by reacting a polyhydroxycompound with acetylene. Examples of divinyl ethers of this type includecompounds in which R² in Formula (6) is an alkyl-substituted methanediylgroup such as —CH(CH₃)— (for example Pluriol® blends such asPluriol®E-200 divinyl ether (BASF Corp., Parsippany, N.J.), for which R²in Formula (6) is ethanediyl and m is 3.8) or an alkyl-substitutedethanediyl (for example —CH₂CH(CH₃)— such as DPE polymeric blendsincluding DPE-2 and DPE-3 (International Specialty Products, Wayne,N.J.)).

Other useful divinyl ethers include compounds in which R² in Formula (6)is polytetrahydrofuryl (poly-THF) or polyoxyalkanediyl, such as thosehaving an average of about 3 monomer units.

Two or more types of polyvinyl ether monomers of Formula (6) may beused. Thus, in certain embodiments, two dithiols of Formula (5) and onepolyvinyl ether monomer of Formula (6), one dithiol of Formula (5) andtwo polyvinyl ether monomers of Formula (6), two dithiols of Formula (5)and two divinyl ether monomers of Formula (6), and more than twocompounds of one or both Formula (5) and Formula (6), may be used toproduce a variety of thiol-functional polythioethers.

In certain embodiments, a polyvinyl ether monomer comprises 20 to lessthan 50 mole percent of the reactants used to prepare a thiol-functionalpolythioether, and in certain embodiments, 30 to less than 50 molepercent.

In certain embodiments provided by the present disclosure, relativeamounts of dithiols and divinyl ethers are selected to yieldpolythioethers having terminal thiol groups. Thus, a dithiol of Formula(5) or a mixture of at least two different dithiols of Formula (5), arereacted with of a divinyl ether of Formula (6) or a mixture of at leasttwo different divinyl ethers of Formula (6) in relative amounts suchthat the molar ratio of thiol groups to vinyl groups is greater than1:1, such as 1.1 to 2.0:1.0.

The reaction between compounds of dithiols and divinyl ethers may becatalyzed by a free radical catalyst. Suitable free radical catalystsinclude, for example, azo compounds, for example azobisnitriles such asazo(bis)isobutyronitrile (AIBN); organic peroxides such as benzoylperoxide and t-butyl peroxide; and inorganic peroxides such as hydrogenperoxide. The catalyst may be a free-radical catalyst, an ioniccatalyst, or ultraviolet radiation. In certain embodiments, the catalystdoes not comprise acidic or basic compounds, and does not produce acidicor basic compounds upon decomposition. Examples of free-radicalcatalysts include azo-type catalyst, such as Vazo®-57 (Du Pont),Vazo®-64 (Du Pont), Vazo®-67 (Du Pont), V-70® (Wako SpecialtyChemicals), and V-65B (Wako Specialty Chemicals). Examples of otherfree-radical catalysts are alkyl peroxides, such as t-butyl peroxide.The reaction may also be effected by irradiation with ultraviolet lighteither with or without a cationic photoinitiating moiety.

Thiol-functional polythioethers provided by the present disclosure maybe prepared by combining at least one compound of Formula (5) and atleast one compound of Formula (6) followed by addition of an appropriatecatalyst, and carrying out the reaction at a temperature from 30° C. to120° C., such as 70° C. to 90° C., for a time from 2 to 24 hours, suchas 2 to 6 hours.

As disclosed herein, thiol-terminated polythioethers may comprise apolyfunctional polythioether, i.e., may have an average functionality ofgreater than 2.0. Suitable polyfunctional thiol-terminatedpolythioethers include, for example, those having the structure ofFormula (7):

B(-A-SH)_(z)  (7)

wherein: (i) A comprises, for example, a structure of Formula (1), (ii)B denotes a z-valent residue of a polyfunctionalizing agent; and (iii) zhas an average value of greater than 2.0, and, in certain embodiments, avalue between 2 and 3, a value between 2 and 4, a value between 3 and 6,and in certain embodiments, is an integer from 3 to 6.

Polyfunctionalizing agents suitable for use in preparing suchpolyfunctional thiol-functional polymers include trifunctionalizingagents, that is, compounds where z is 3. Suitable trifunctionalizingagents include, for example, triallyl cyanurate (TAC),1,2,3-propanetrithiol, isocyanurate-containing trithiols, andcombinations thereof, as disclosed in U.S. Publication No. 2010/0010133at paragraphs [0102]-[0105], the cited portion of which is incorporatedherein by reference. Other useful polyfunctionalizing agents includetrimethylolpropane trivinyl ether, and the polythiols described in U.S.Pat. Nos. 4,366,307; 4,609,762; and 5,225,472. Mixtures ofpolyfunctionalizing agents may also be used.

As a result, thiol-functional polythioethers suitable for use inembodiments provided by the present disclosure may have a wide range ofaverage functionality. For example, trifunctionalizing agents may affordaverage functionalities from 2.05 to 3.0, such as from 2.1 to 2.6. Widerranges of average functionality may be achieved by using tetrafunctionalor higher functionality polyfunctionalizing agents. Functionality mayalso be affected by factors such as stoichiometry, as will be understoodby those skilled in the art.

Thiol-functional polythioethers having a functionality greater than 2.0may be prepared in a manner similar to the difunctional thiol-functionalpolythioethers described in U.S. Publication No. 2010/0010133. Incertain embodiments, polythioethers may be prepared by combining (i) oneor more dithiols described herein, with (ii) one or more divinyl ethersdescribed herein, and (iii) one or more polyfunctionalizing agents. Themixture may then be reacted, optionally in the presence of a suitablecatalyst, to afford a thiol-functional polythioether having afunctionality greater than 2.0.

Thus, in certain embodiments, a thiol-terminated polythioether comprisesthe reaction product of reactants comprising:

(a) a dithiol of Formula (5):

HS—R¹—SH  (5)

-   -   wherein:        -   R¹ is selected from C₂₋₆ alkanediyl, C₆₋₈ cycloalkanediyl,            C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈ heterocycloalkanediyl, and            —[—(CHR³)_(s)—X-]_(q)—(CHR³)_(r)—; wherein:            -   each R³ is independently selected from hydrogen and                methyl;            -   each X is independently selected from —O—, —S—, —NH—,                and —NR— wherein R is selected from hydrogen and methyl;            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5; and            -   r is an integer from 2 to 10; and

(b) a divinyl ether of Formula (6):

CH₂═CH—O—[—R²—O—]_(m)—CH═CH₂  (6)

-   -   wherein:        -   each R² is independently selected from C₁₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and            —[(CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined above;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6.            And, in certain embodiments, the reactants comprise (c) a            polyfunctional compound such as a polyfunctional compound            B(—V)_(z), where B, —V, and z are as defined herein.

Thiol-terminated polythioethers provided by the present disclosurerepresent thiol-terminated polythioethers having a molecular weightdistribution. In certain embodiments, useful thiol-terminatedpolythioethers can exhibit a number average molecular weight rangingfrom 500 Daltons to 20,000 Daltons, in certain embodiments, from 2,000Daltons to 5,000 Daltons, and in certain embodiments, from 3,000 Daltonsto 4,000 Daltons. In certain embodiments, useful thiol-terminatedpolythioethers exhibit a polydispersity (M_(w)/M_(n); weight averagemolecular weight/number average molecular weight) ranging from 1 to 20,and in certain embodiments, from 1 to 5. The molecular weightdistribution of thiol-terminated polythioethers may be characterized bygel permeation chromatography.

In certain embodiments, thiol-functional polythioethers provided by thepresent disclosure are essentially free, or free, of sulfone, esterand/or disulfide linkages. As used herein, “essentially free of sulfone,ester, and/or disulfide linkages” means that less than 2 mole percent ofthe linkages in the thiol-functional polymer are sulfone, ester, and/ordisulfide linkages. As a result, in certain embodiments, the resultingthiol-functional polythioethers are also essentially free, or free, ofsulfone, ester, and/or disulfide linkages.

To prepare a sulfur-containing Michael acceptor adduct, asulfur-containing polymer such as those disclosed herein may be reactedwith (b) a compound having a group that is reactive with the terminalgroups of the sulfur-containing polymer and a Michael acceptor group.

In certain embodiments, a Michael acceptor group is selected from avinyl ketone, a vinyl sulfone, a quinone, an enamine, a ketimine, analdimine, and an oxazolidine. In certain embodiments, a Michael acceptorgroup is a vinyl ketone, and in certain embodiments, a vinyl sulfonesuch as divinyl sulfone. In embodiments in which the compound having aMichael acceptor group is divinyl sulfone, the sulfur-containing polymermay be thiol-terminated such as a thiol-terminated polythioether, athiol-terminated polysulfide, or a combination thereof.

The reaction between a sulfur-containing polymer and a compound having aMichael acceptor group and a group that is reactive with a terminalgroup of the sulfur-containing polymer can be performed in the presenceof an appropriate catalyst.

In certain embodiments, compositions provided by the present disclosurecomprise a catalyst such as an amine catalyst. For example, inembodiments in which the sulfur-containing polymer is thiol-terminatedand the compound is a difunctional Michael acceptor, the reaction maytake place in the presence of an amine catalyst. Examples of suitableamine catalysts include, for example, triethylenediamine(1,4-diazabicyclo[2.2.2]octane, DABCO), dimethylcyclohexylamine (DMCHA),dimethylethanolamine (DMEA), bis-(2-dimethylaminoethyl)ether,N-ethylmorpholine, triethylamine, 1,8-diazabicyclo[5.4.0]undecene-7(DBU), pentamethyldiethylenetriamine (PMDETA), benzyldimethylamine(BDMA), N,N,N′-trimethyl-N′-hydroxyethyl-bis(aminoethyl)ether, andN′-(3-(dimethylamino)propyl)-N,N-dimethyl-1,3-propanediamine.

Compositions

Michael addition chemistries may be employed in a variety of ways inconjunction with sulfur-containing polymers to provide curablecompositions. For example, a curable composition provided by the presentdisclosure may comprise (a) a sulfur-containing polymer and a Michaelacceptor curing agent; (b) a sulfur-containing Michael acceptor adductand a curing agent comprising at least two terminal groups that arereactive with Michael acceptor groups; or (c) a sulfur-containingpolymer and a curing agent comprising a combination of a monomericMichael acceptor and a sulfur-containing Michael acceptor adduct.

Sulfur-Containing Polymer and Michael Acceptor Curing Agent

In certain embodiments, compositions provided by the present disclosurecomprise a sulfur-containing polymer and a Michael acceptor curingagent. A sulfur-containing polymer may be a polythioether or combinationof polythioethers having terminal groups reactive with the Michaelacceptor; a polysulfide or combination of polysulfides having terminalgroups reactive with the Michael acceptor; or a combination of any ofthe foregoing. In certain embodiments, a sulfur-containing polymer isthiol-terminated. In such embodiments, a Michael acceptor will bepolyfunctional and have Michael acceptor groups reactive with theterminal groups of the sulfur-containing polymer.

In certain embodiments, a sulfur-containing polymer comprises athiol-terminated polythioether, including any of the thiol-terminatedpolythioethers disclosed herein, such as a thiol-terminatedpolythioether of Formula (1). In certain embodiments, asulfur-containing polymer comprises a thiol-terminated polythioether,such as a thiol-terminated polythioether of Formula (4), Formula (4a),or a combination thereof. In certain embodiments, a sulfur-containingpolymer is selected from a difunctional sulfur-containing polymer, atrifunctional-containing polymer and a combination of thereof. Incertain embodiments, a thiol-terminated polymer comprises a mixture ofsulfur-containing polymers having an average functionality from 2 to 3,and in certain embodiments, from 2.2 to 2.8. In certain embodiments, athiol-terminated polythioether comprises Permapol® 3.1E, available fromPRC-DeSoto International.

A polyfunctional Michael acceptor has at least two Michael acceptorgroups. A polyfunctional Michael acceptor may have an average Michaelacceptor functionality from 2 to 6, from 2 to 4, from 2 to 3, and incertain embodiments, from 2.05 to 2.5. In certain embodiments, apolyfunctional Michael acceptor is difunctional, such as, divinyl ketoneand divinyl sulfone. A Michael acceptor having a functionality greaterthan two may be prepared by reacting a compound having a Michaelacceptor group and a group reactive with terminal groups of apolyfunctionalizing agent such as those disclosed herein, usingappropriate reaction conditions.

In certain embodiments where a Michael acceptor is used as a curingagent, the molecular weight of the Michael acceptor is less than 600Daltons, less than 400 Daltons, and in certain embodiments, less than200 Daltons.

In certain embodiments, a Michael acceptor comprises from about 0.5 wt %to about 20 wt % of the composition, from about 1 wt % to about 10 wt %,from about 2 wt % to about 8 wt %, from about 2 wt % to about 6 wt %,and in certain embodiments, from about 3 wt % to about 5 wt %, where wt% is based on the total dry solids weight of the composition.

Sulfur-Containing Michael Acceptor Adduct and a Curing Agent

In certain embodiments, a composition comprises a sulfur-containingMichael acceptor adduct provided by the present disclosure and asulfur-containing polymer curing agent.

In such compositions a sulfur-containing adduct comprises any of thosedisclosed herein. In certain embodiments, a sulfur-containing adductcomprises a polythioether adduct, and in certain embodiments apolythioether adduct has an average functionality from 2 to 3, from 2.2to 2.8, and in certain embodiments, from 2.4 to 2.6. In certainembodiments, a sulfur-containing adduct has an average functionality of2.

In certain embodiments, a sulfur-containing Michael acceptor adductcomprises a compound of Formula (3), Formula (3a), or a combinationthereof, and the sulfur-containing polymer curing agent comprises apolythioether of Formula (4), Formula (4a), or a combination thereof. Incertain embodiments, the sulfur-containing adduct comprises the Michaelacceptor adduct of Permapol® 3.1E. In certain embodiments, thesulfur-containing polymer curing agent comprises Permapol® 3.1E.

In certain embodiments, a sulfur-containing Michael acceptor adductcomprises a compound of Formula (3), Formula (3a), or a combinationthereof, and the sulfur-containing polymer curing agent comprises apolysulfide. In certain embodiments, the sulfur-containing adductcomprises the Michael acceptor adduct of Permapol® 3.1E. In certainembodiments, the sulfur-containing polymer comprises a polysulfideselected from a Thiokol-LP® polysulfide, a Thioplast® polysulfide, and acombination thereof.

In such compositions the Michael acceptor groups of the adduct arereactive with the terminal groups of the sulfur-containing polymer. Forexample, the Michael acceptor groups may be activated alkenyl groups,e.g., Michael acceptor groups, and the sulfur-containing polymercomprises terminal thiol groups.

A sulfur-containing polymer used as a curing agent comprises at leasttwo terminal groups reactive with Michael acceptor groups. Asulfur-containing polymer used as a curing agent in such compositionsmay comprise a polythioether including any of those disclosed herein, apolysulfide including any of those disclosed herein, or a combinationthereof. The sulfur-containing polymer may have an average functionalityof about 2 or any functionality from about 2 and about 6, such as fromabout 2 to about 4, or from about 2 to about 3.

In certain embodiments, the sulfur-containing polymer curing agentcomprises a thiol-terminated polythioether such as, for example,Permapol® 3.1E. In certain embodiments, the sulfur-containing polymercomprises a thiol-terminated polysulfide such as, for example, aThiokol-LP® polysulfide, a Thioplast® polysulfide, or a combinationthereof.

In such embodiments, when used as a curing agent, a sulfur-containingpolymer, comprises from about 20 wt % to about 90 wt % of thecomposition, from about 30 wt % to about 80 wt %, from about 40 wt % toabout 60 wt %, and in certain embodiments, about 50 wt %, where wt % isbased on the total dry weight of the composition.

In such embodiments, a sulfur-containing Michael acceptor adductcomprises from about 20 wt % to about 90 wt % of the composition, fromabout 30 wt % to about 80 wt %, from about 40 wt % to about 60 wt %, andin certain embodiments, about 50 wt %, where wt % is based on the totaldry weight of the composition.

Compositions comprising a sulfur-containing Michael acceptor adduct anda sulfur-containing polymer curing agent may comprise a catalyst such asan amine catalyst including any of those disclosed herein.

In certain embodiments, a composition comprises a polythioether adductand a curing agent. A polythioether adduct includes any of thosedisclosed herein, such as polythioether adducts of Formula (3), Formula(3a), and combinations thereof.

In certain embodiments of such compositions, the composition comprises asulfur-containing Michael acceptor adduct provided by the presentdisclosure and a curing agent selected from a sulfur-containing polymercomprising at least two terminal groups reactive with Michael acceptorgroups, a monomeric thiol, a polythiol, a polyamine, a blockedpolyamine, and a combination of any of the foregoing. In certainembodiments, a curing agent comprises a sulfur-containing polymercomprising at least two terminal groups reactive with Michael acceptorgroups; in certain embodiments a monomeric thiol; in certain embodimentsa polythiol; in certain embodiments a polyamine; and in certainembodiments, a blocked polyamine. In certain embodiments of suchcompositions, a curing agent comprises a sulfur-containing polymercomprising at least two terminal groups reactive with Michael acceptorgroups and a compound having at least two terminal groups reactive withMichael acceptor groups selected from a monomeric thiol, a polythiol, apolyamine, a blocked polyamine, and a combination of any of theforegoing.

In certain embodiments, a sulfur-containing polymer comprising at leasttwo terminal groups reactive with Michael acceptor groups is selectedfrom a polythioether polymer comprising at least two terminal groupsreactive with Michael acceptor groups, a polysulfide polymer comprisingat least two terminal groups reactive with Michael acceptor groups, anda combination thereof. In certain embodiments, the terminal groupsreactive with Michael acceptor groups are terminal thiol groups. In suchembodiments, a thiol-terminated polythioether may be selected from apolythioether of Formula (4), a polythioether of Formula (4a), and acombination thereof. In certain embodiments, the sulfur-containingpolymer curing agent comprises a thiol-terminated polysulfide such as,for example, Thiokol-LP® and Thioplast® polysulfide polymers.

In certain compositions, the curing agent comprises a monomeric thiol. Amonomeric thiol refers to a compound having at least two terminal thiolgroups. Examples of monomeric thiols include dithiols of Formula (5).Polythiols refer to higher molecular weight compounds having terminalthiol groups and thiol groups in the backbone.

Examples of polyamines include, for example, aliphatic polyamines,cycloaliphatic polyamines, aromatic polyamines and mixtures thereof. Incertain embodiments, the polyamine can include a polyamine having atleast two functional groups independently chosen from primary amine(—NH₂), secondary amine (—NH—) and combinations thereof. In certainembodiments, the polyamine has at least two primary amine groups.

In certain embodiments, a polyamine is a sulfur-containing polyamine.Examples of suitable sulfur-containing polyamines are isomers ofbenzenediamine-bis(methylthio)-, such as1,3-benzenediamine-4-methyl-2,6-bis(methylthio)- and1,3-benzenediamine-2-methyl-4,6-bis(methylthio)-, having the structure:

Such sulfur-containing polyamines are commercially available, forexample, from Albemarle Corporation under the tradename Ethacure® 300.

Suitable polyamines also include, for example, polyamines having thefollowing structure:

wherein each R¹¹ and each R¹² are independently selected from methyl,ethyl, propyl, and isopropyl groups, and each R¹³ is independentlyselected from hydrogen and chlorine. Examples of suitableamine-containing curing agents include the following compounds availablefrom Lonza Ltd. (Basel, Switzerland): Lonzacure® M-DIPA, Lonzacure®M-DMA, Lonzacure® M-MEA, Lonzacure® M-DEA, Lonzacure® M-MIPA, Lonzacure®M-CDEA.

In certain embodiments, a polyamine comprises a diamine, such as4,4′-methylenebis(3-chloro-2,6-diethylaniline) (Lonzacure® M-CDEA),2,4-diamino-3,5-diethyl-toluene, 2,6-diamino-3,5-diethyl-toluene andmixtures thereof (collectively diethyltoluenediamine or DETDA), asulfur-containing diamine, such as Ethacure® 300,4,4′-methylene-bis-(2-chloroaniline) and mixtures thereof. Othersuitable diamines include 4,4′-methylene-bis(dialkylaniline),4,4′-methylene-bis(2,6-dimethylaniline),4,4′-methylene-bis(2,6-diethylaniline),4,4′-methylene-bis(2-ethyl-6-methylaniline),4,4′-methylene-bis(2,6-diisopropylaniline),4,4′-methylene-bis(2-isopropyl-6-methylaniline),4,4′-methylene-bis(2,6-diethyl-3-chloroaniline), and combinations of anyof the foregoing.

Further, examples of suitable polyamines include ethyleneamines, suchas, ethylenediamine (EDA), diethylenetriamine (DETA),triethylenetetramine (TETA), tetraethylenepentamine (TEPA),pentaethylenehexamine (PEHA), piperazine, morpholine, substitutedmorpholine, piperidine, substituted piperidine, diethylenediamine(DEDA), 2-amino-1-ethylpiperazine, and combinations thereof. In certainembodiments, a polyamine may be selected from one or more isomers ofC₁₋₃ dialkyl toluenediamine, such as, 3,5-dimethyl-2,4-toluenediamine,3,5-dimethyl-2,6-toluenediamine, 3,5-diethyl-2,4-toluenediamine,3,5-diethyl-2,6-toluenediamine, 3,5-diisopropyl-2,4-toluenediamine,3,5-diisopropyl-2,6-toluenediamine, and combinations thereof. In certainembodiments, a polyamine may be selected from methylene dianiline,trimethyleneglycol di(para-aminobenzoate), and combinations thereof.

In certain embodiments, a polyamine includes a compound having thestructure:

In certain embodiments, a polyamine includes one or more methylene bisanilines, one or more aniline sulfides, and/or one or more bianilineswhich can be represented by the general structures disclosed, forexample, in paragraph [0072] of U.S. Publication No. 2011/0092639, whichis incorporated by reference herein.

In certain embodiments, a polyamine includes compounds represented bythe general structure:

where R²⁰, R²¹, R²², and R²³ are independently selected from C₁₋₃ alkyl,CH₃—S— and halogen, such as but not limited to chlorine or bromine. Incertain embodiments, a polyamine represented by the immediatelypreceding structure can be diethyl toluene diamine (DETDA) wherein R²³is methyl, R²⁰ and R²¹ are each ethyl, and R²² is hydrogen. In certainembodiments, the polyamine is 4,4′-methylenedianiline.

Examples of blocked polyamines include ketimines, enamines,oxazolidines, aldimines, and imidazolidines. In certain embodiments, theblocked polyamine is Vestamin® A 139.

Sulfur-Containing Polymer Adduct, Sulfur-Containing Polymer, and aCompound Having at Least Two Michael Acceptor Groups

In certain embodiments, a composition comprises a sulfur-containingpolymer, and a sulfur-containing Michael acceptor adduct. In certainembodiments, a composition comprises a sulfur-containing polymer, apolyfunctional Michael acceptor, and a sulfur-containing Michaelacceptor adduct.

In such compositions, a sulfur-containing polymer comprises at least twoterminal groups reactive with Michael acceptor groups. In suchcompositions, the sulfur-containing polymer may be selected from apolythioether polymer, a polysulfide polymer, or a combination thereof,including a suitable polythioether polymer or polysulfide polymerprovided by the present disclosure.

In certain embodiments, a sulfur-containing polymer is selected suchthat the terminal groups are reactive with the polyfunctional Michaelacceptor and the sulfur-containing Michael acceptor adduct. In certainembodiments, a sulfur-containing polymer comprises terminal thiol groupsincluding any of the thiol-terminated polythioethers, thiol-terminatedpolysulfides, and combinations thereof disclosed herein.

In certain embodiments of such compositions, a sulfur-containing polymeradduct comprises a polythioether polymer adduct provided by the presentdisclosure, a polysulfide polymer adduct provided by the presentdisclosure, or a combination thereof.

When a composition comprises a polyfunctional monomeric Michaelacceptor, any suitable monomeric Michael acceptor having at least twoMichael acceptor groups such as, for example, divinyl sulfone or otherMichael acceptors including any of those disclosed herein may be used.

In certain embodiments, a sulfur-containing polymer is selected from apolythioether of Formula (3), Formula (3a), and a combination thereof; apolyfunctional Michael acceptor adduct is selected from an adduct ofFormula (4), Formula (4a), and a combination thereof; and apolyfunctional monomeric Michael acceptor is selected from a compoundhaving two or more activated alkenyl groups such as a vinyl ketone or avinyl sulfone, such as divinyl sulfone.

In such embodiments, the polyfunctional Michael acceptor and Michaelacceptor adduct comprise 10 wt % to 90 wt % of the composition, from 20wt % to 80 wt %, from 30 wt % to 70 wt %, and in certain embodiments,from 40 wt % to 60 wt %, where wt % is based on the total dry solidsweight of the composition.

Compositions comprising a sulfur-containing polymer, a polyfunctionalMichael acceptor, and a sulfur-containing polymer adduct may comprise acatalyst such as an amine catalyst including any of those disclosedherein.

Epoxy Blend

In certain embodiments, compositions provided by the present disclosurecomprise an epoxy curing agent. Thus, in addition to a Michael acceptorcuring agent, a sulfur-containing polymer curing agent, and/or asulfur-containing Michael acceptor adduct curing agent, a compositionmay comprise one or more polyepoxy curing agents. Examples of suitableepoxies include, for example, polyepoxide resins such as hydantoindiepoxide, diglycidyl ether of bisphenol-A, diglycidyl ether ofbisphenol-F, Novolac® type epoxides such as DEN™ 438 (available fromDow), certain epoxidized unsaturated resins, and combinations of any ofthe foregoing. A polyepoxide refers to a compound having two or morereactive epoxy groups.

In certain embodiments, a polyepoxy curing agent comprises anepoxy-functional polymer. Examples of suitable epoxy-functional polymersinclude the epoxy-functional polyformal polymers disclosed in U.S.patent application Ser. No. 13/050,988 and epoxy-functionalpolythioether polymers disclosed in U.S. Pat. No. 7,671,145. In general,when used as a curing agent, an epoxy-functional polymer has a molecularweight less than about 2,000 Daltons, less than about 1,500, Daltons,less than about 1,000 Daltons, and in certain embodiments, less thanabout 500 Daltons.

In such compositions, an epoxy may comprise about 0.5 wt % to about 20wt % of the composition, from about 1 wt % to about 10 wt %, from about2 wt % to about 8 wt %, from about 2 wt % to about 6 wt %, and incertain embodiments, from about 3 wt % to about 5 wt %, where wt % isbased on the total solids weight of the composition.

Isocyanate Blend

In certain embodiments, compositions provided by the present disclosurecomprise an isocyanate curing agent. Thus, in addition to a Michaelacceptor curing agent, a sulfur-containing polymer curing agent, and/ora sulfur-containing Michael acceptor adduct curing agent, a compositionmay comprise one or more polyisocyanate curing agents that are reactivewith thiol groups but not reactive with Michael acceptor groups such asvinyl sulfone groups. Examples of suitable isocyanate curing agentsinclude allyl isocyanate, 3-isopropenyl-α,α-dimethylbenzyl isocyanate,toluene diisocyanate, and combinations of any of the foregoing.Isocyanate curing agents are commercially available and include, forexample, products under the tradenames Baydur® (Bayer MaterialScience),Desmodur® (Bayer MaterialScience), Solubond® (DSM), ECCO (ECCO),Vestanat® (Evonik), Irodur® (Huntsman), Rhodocoat™ (Perstorp), andVanchem® (V.T. Vanderbilt). In certain embodiments, a polyisocyanatecuring agent comprises isocyanate groups that are reactive with thiolgroups and that are less reactive with Michael acceptor groups.

In certain embodiments, an isocyanate curing agent comprises anisocyanate-functional polymer. Examples of suitableisocyanate-functional polymers include the isocyanate-functionalpolyformal polymers disclosed in U.S. patent application Ser. No.13/051,002. In general, when used as a curing agent, anisocyanate-functional polymer has a molecular weight less than about2,000 Daltons, less than about 1,500, Daltons, less than about 1,000Daltons, and in certain embodiments, less than about 500 Daltons.

In such compositions, an epoxy may comprise about 0.5 wt % to about 20wt % of the composition, from about 1 wt % to about 10 wt %, from about2 wt % to about 8 wt %, from about 2 wt % to about 6 wt %, and incertain embodiments, from about 3 wt % to about 5 wt % of thecomposition, where wt % is based on the total solids weight of thecomposition.

Hydroxyl and Amine Curing

Sulfur-containing Michael acceptor adducts provided by the presentdisclosure may also be modified for use in particular applications andcuring chemistries. For example, spray seal applications require rapidcuring without heating. Amine-based systems using epoxy curing agentsare well suited for such applications. Accordingly, sulfur-containingMichael acceptor adducts may be adapted to other curing chemistries bymodifying or capping the terminal Michael acceptor groups with, forexample, hydroxyl groups or amine groups.

Hydroxyl-terminated sulfur-containing adducts may be prepared byreacting a sulfur-containing Michael acceptor adduct provided by thepresent disclosure such as an adduct of Formulae (1), Formula (3), orFormula (3a), and a compound having a terminal thiol group and aterminal hydroxyl group. In certain embodiments, a compound having aterminal thiol group and a terminal hydroxyl group has the structureHS—R¹¹—OH, where R¹¹ is selected from C₂₋₆ alkanediyl, C₆₋₈cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈heterocycloalkanediyl, C₆₋₈ arenediyl, C₆₋₁₀ alkanearenediyl, C₅₋₈heteroarenediyl, and —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, where q, r, s,X, and R³ are defined as for Formula (5). In certain embodiments, asulfur-containing adduct is derived from Permapol® 3.1E. The reactionmay take place in the presence of a catalyst at a temperature from about25° C. to about 50° C.

In certain embodiments, a hydroxyl-terminated sulfur-containing adductcomprises a hydroxyl-terminated polythioether adduct of Formula (8), ahydroxyl-terminated polythioether adduct of Formula (8a), and acombination thereof:

R⁹—R^(6′)—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—R^(6′)—R⁹  (8)

{R⁹—R^(6′)—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′-}_(z)B  (8a)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NHR—,            wherein R is selected from hydrogen and methyl;    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60;    -   p is an integer from 2 to 6;    -   B represents a core of a z-valent, vinyl-terminated        polyfunctionalizing agent B(—V)_(z) wherein:        -   z is an integer from 3 to 6; and        -   each V is a group comprising a terminal vinyl group;    -   each —V′— is derived from the reaction of —V with a thiol;    -   each —R^(6′)— is —CH₂—C(R⁴)₂—S(O)₂—C(R⁴)₂—CH₂—, wherein each R⁴        is independently selected from hydrogen and C₁₋₃ alkyl; and    -   each R⁹— is a moiety having a terminal hydroxyl group.

In certain embodiments of Formula (8) and Formula (8a), R⁹ is —S—R¹¹—OH,wherein R¹¹ is defined herein.

In certain embodiments, compositions comprise one or morehydroxyl-terminated sulfur-containing adducts and one or morepolyisocyanate curing agents. Examples of suitable isocyanate curingagents include toluene diisocyanate, and combinations of any of theforegoing. Isocyanate curing agents are commercially available andinclude, for example, products under the tradenames Baydur® (BayerMaterialScience), Desmodur® (Bayer MaterialScience), Solubond® (DSM),ECCO (ECCO), Vestanat® (Evonik), Irodur® (Huntsman), Rhodocoat™(Perstorp), and Vanchem® (V.T. Vanderbilt).

Amine-terminated sulfur-containing adducts may be prepared by reacting asulfur-containing Michael accepter adduct provided by the presentdisclosure such as an adduct of Formulae (1), (3), or (3a), and acompound having a terminal thiol group and a terminal amine group. Incertain embodiments, a compound having a terminal thiol group and aterminal hydroxyl group has the structure HS—R¹¹—N(R¹²)H, where R¹¹ isselected from C₂₋₆ alkanediyl, C₆₋₈ cycloalkanediyl, C₆₋₁₀alkanecycloalkanediyl, C₅₋₈ heterocycloalkanediyl, C₆₋₈ arenediyl, C₆₋₁₀alkanerenediyl, C₅₋₈ heteroarenediyl, and—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, where q, r, s, X, and R³ are definedas for Formula (5). In certain embodiments, R¹² is selected fromhydrogen and C₁₋₃ alkyl, and in certain embodiments, R¹² is hydrogen. Incertain embodiments, a sulfur containing adduct is derived fromPermapol® 3.1E. The reaction may take place in the presence of acatalyst at a temperature from about 25° C. to about 50° C.

In certain embodiments, an amine-terminated sulfur-containing adductcomprises an amine-terminated polythioether adduct of Formula (8), anamine-terminated polythioether adduct of Formula (8a), and a combinationthereof:

R⁹—R^(6′)—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—R^(6′)—R⁹  (8)

{R⁹—R^(6′)—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′-}_(z)B  (8a)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NHR—,            wherein R is selected from hydrogen and methyl;    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[(—CHR³—)_(s)—X-]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60;    -   p is an integer from 2 to 6;    -   B represents a core of a z-valent, vinyl-terminated        polyfunctionalizing agent B(—V)_(z) wherein:        -   z is an integer from 3 to 6; and        -   each V is a group comprising a terminal vinyl group;    -   each —V′— is derived from the reaction of —V with a thiol;    -   each —R^(6′)— is —CH₂—C(R⁴)₂—S(O)₂—C(R⁴)₂—CH₂—, wherein each R⁴        is independently selected from hydrogen and C₁₋₃ alkyl; and    -   each R⁹— is a moiety having a terminal amine group.

In certain embodiments, R⁹ is HS—R¹¹—N(R¹²)H, and in certain embodimentsof Formula (8) and Formula (8a), R⁹ is —S—R¹¹—NH₂.

In certain embodiments, compositions comprise one or moreamine-terminated sulfur-containing adducts and one or morepolyisocyanate curing agents such as any of those disclosed herein.

Compositions

Compositions provided by the present disclosure may include one or morecatalysts. Catalysts appropriate for use in reactions between Michaelacceptors such as activated alkenyl groups and thiol groups include basecatalysts such as amines. Examples of suitable amine catalysts include,for example, triethylenediamine (1,4-diazabicyclo [2.2.2]octane, DABCO),dimethylcyclohexylamine (DMCHA), dimethylethanolamine (DMEA),bis-(2-dimethylaminoethyl)ether, N-ethylmorpholine, triethylamine,1,8-diazabicyclo[5.4.0]undecene-7 (DBU), pentamethyldiethylenetriamine(PMDETA), benzyldimethylamine (BDMA),N,N,N′-trimethyl-N′-hydroxyethyl-bis(aminoethyl)ether, andN′-(3-(dimethylamino)propyl)-N,N-dimethyl-1,3-propanediamine.

In compositions comprising epoxies, the composition may comprise a basecatalyst, including amine catalysts such as any of those disclosedherein.

In certain embodiments, compositions provided by the present disclosurecomprise one or more than one adhesion promoters. A one or moreadditional adhesion promoter may be present in amount from 0.1 wt % to15 wt % of a composition, less than 5 wt %, less than 2 wt %, and incertain embodiments, less than 1 wt %, based on the total dry weight ofthe composition. Examples of adhesion promoters include phenolics, suchas Methylon® phenolic resin, and organosilanes, such as epoxy, mercaptoor amino functional silanes, such as Silquest® A-187 and Silquest®A-1100. Other useful adhesion promoters are known in the art.

Compositions provided by the present disclosure may comprise one or moredifferent types of filler. Suitable fillers include those commonly knownin the art, including inorganic fillers, such as carbon black andcalcium carbonate (CaCO₃), silica, polymer powders, and lightweightfillers. Suitable lightweight fillers include, for example, thosedescribed in U.S. Pat. No. 6,525,168. In certain embodiments, acomposition includes 5 wt % to 60 wt % of the filler or combination offillers, 10 wt % to 50 wt %, and in certain embodiments, from 20 wt % to40 wt %, based on the total dry weight of the composition. Compositionsprovided by the present disclosure may further include one or morecolorants, thixotropic agents, accelerators, fire retardants, adhesionpromoters, solvents, masking agents, or a combination of any of theforegoing. As can be appreciated, fillers and additives employed in acomposition may be selected so as to be compatible with each other aswell as the polymeric component, curing agent, and or catalyst.

In certain embodiments, compositions provided by the present disclosureinclude low density filler particles. As used herein, low density, whenused with reference to such particles means that the particles have aspecific gravity of no more than 0.7, in certain embodiments no morethan 0.25, and in certain embodiments, no more than 0.1. Suitablelightweight filler particles often fall within twocategories—microspheres and amorphous particles. The specific gravity ofmicrospheres may range from 0.1 to 0.7 and include, for example,polystyrene foam, microspheres of polyacrylates and polyolefins, andsilica microspheres having particle sizes ranging from 5 to 100 micronsand a specific gravity of 0.25 (Eccospheres®). Other examples includealumina/silica microspheres having particle sizes in the range of 5 to300 microns and a specific gravity of 0.7 (Fillite®), aluminum silicatemicrospheres having a specific gravity of from about 0.45 to about 0.7(Z-Light®), calcium carbonate-coated polyvinylidene copolymermicrospheres having a specific gravity of 0.13 (Dualite® 6001AE), andcalcium carbonate coated acrylonitrile copolymer microspheres such asDualite® E135, having an average particle size of about 40 m and adensity of 0.135 g/cc (Henkel). Suitable fillers for decreasing thespecific gravity of the composition include, for example, hollowmicrospheres such as Expancel® microspheres (available from AkzoNobel)or Dualite® low density polymer microspheres (available from Henkel). Incertain embodiments, compositions provided by the present disclosureinclude lightweight filler particles comprising an exterior surfacecoated with a thin coating, such as those described in U.S. PublicationNo. 2010/0041839 at paragraphs [0016]-[0052], the cited portion of whichis incorporated herein by reference.

In certain embodiments, a low density filler comprises less than 2 wt %of a composition, less than 1.5 wt %, less than 1.0 wt %, less than 0.8wt %, less than 0.75 wt %, less than 0.7 wt % and in certainembodiments, less than 0.5 wt % of a composition, where wt % is based onthe total dry solids weight of the composition.

In certain embodiments, compositions provided by the present disclosurecomprise at least one filler that is effective in reducing the specificgravity of the composition. In certain embodiments, the specific gravityof a composition is from 0.8 to 1, 0.7 to 0.9, from 0.75 to 0.85, and incertain embodiments, is 0.8. In certain embodiments, the specificgravity of a composition is less than about 0.9, less than about 0.8,less than about 0.75, less than about 0.7, less than about 0.65, lessthan about 0.6, and in certain embodiments, less than about 0.55.

In certain embodiments, compositions provided by the present disclosurecomprise an electrically conductive filler. Electrical conductivity andEMI/RFI shielding effectiveness can be imparted to composition byincorporating conductive materials within the polymer. The conductiveelements can include, for example, metal or metal-plated particles,fabrics, meshes, fibers, and combinations thereof. The metal can be inthe form of, for example, filaments, particles, flakes, or spheres.Examples of metals include copper, nickel, silver, aluminum, tin, andsteel. Other conductive materials that can be used to impart EMI/RFIshielding effectiveness to polymer compositions include conductiveparticles or fibers comprising carbon or graphite. Conductive polymerssuch as polythiophenes, polypyrroles, polyaniline, poly(p-phenylene)vinylene, polyphenylene sulfide, polyphenylene, and polyacetylene canalso be used.

Examples of electrically non-conductive fillers include materials suchas, but not limited to, calcium carbonate, mica, polyamide, fumedsilica, molecular sieve powder, microspheres, titanium dioxide, chalks,alkaline blacks, cellulose, zinc sulfide, heavy spar, alkaline earthoxides, alkaline earth hydroxides, and the like. Fillers also includehigh band gap materials such as zinc sulfide and inorganic bariumcompounds. In certain embodiments, an electrically conductive basecomposition can comprise an amount of electrically non-conductive fillerranging from 2 wt % to 10 wt % based on the total weight of the basecomposition, and in certain embodiments, can range from 3 wt % to 7 wt%. In certain embodiments, a curing agent composition can comprise anamount of electrically non-conductive filler ranging from less than 6 wt% and in certain embodiments ranging from 0.5% to 4% by weight, based onthe total weight of the curing agent composition.

Fillers used to impart electrical conductivity and EMI/RFI shieldingeffectiveness to polymer compositions are well known in the art.Examples of electrically conductive fillers include electricallyconductive noble metal-based fillers such as pure silver; noblemetal-plated noble metals such as silver-plated gold; noble metal-platednon-noble metals such as silver plated cooper, nickel or aluminum, forexample, silver-plated aluminum core particles or platinum-plated copperparticles; noble-metal plated glass, plastic or ceramics such assilver-plated glass microspheres, noble-metal plated aluminum ornoble-metal plated plastic microspheres; noble-metal plated mica; andother such noble-metal conductive fillers. Non-noble metal-basedmaterials can also be used and include, for example, non-noblemetal-plated non-noble metals such as copper-coated iron particles ornickel plated copper; non-noble metals, e.g., copper, aluminum, nickel,cobalt; non-noble-metal-plated-non-metals, e.g., nickel-plated graphiteand non-metal materials such as carbon black and graphite. Combinationsof electrically conductive fillers can also be used to meet the desiredconductivity, EMI/RFI shielding effectiveness, hardness, and otherproperties suitable for a particular application.

The shape and size of the electrically conductive fillers used in thecompositions of the present disclosure can be any appropriate shape andsize to impart EMI/RFI shielding effectiveness to the cured composition.For example, fillers can be of any shape that is generally used in themanufacture of electrically conductive fillers, including spherical,flake, platelet, particle, powder, irregular, fiber, and the like. Incertain sealant compositions of the disclosure, a base composition cancomprise Ni-coated graphite as a particle, powder or flake. In certainembodiments, the amount of Ni-coated graphite in a base composition canrange from 40 wt % to 80 wt %, and in certain embodiments can range from50 wt % to 70 wt %, based on the total weight of the base composition.In certain embodiments, an electrically conductive filler can compriseNi fiber. Ni fiber can have a diameter ranging from 10 m to 50 m andhave a length ranging from 250 μm to 750 μm. A base composition cancomprise, for example, an amount of Ni fiber ranging from 2 wt % to 10wt %, and in certain embodiments, from 4 wt % to 8 wt %, based on thetotal weight of the base composition.

Carbon fibers, particularly graphitized carbon fibers, can also be usedto impart electrical conductivity to compositions of the presentdisclosure. Carbon fibers formed by vapor phase pyrolysis methods andgraphitized by heat treatment and which are hollow or solid with a fiberdiameter ranging from 0.1 micron to several microns, have highelectrical conductivity. As disclosed in U.S. Pat. No. 6,184,280, carbonmicrofibers, nanotubes or carbon fibrils having an outer diameter ofless than 0.1 μm to tens of nanometers can be used as electricallyconductive fillers. An example of graphitized carbon fiber suitable forconductive compositions of the present disclosure include PANEX 30MF(Zoltek Companies, Inc., St. Louis, Mo.), a 0.921 μm diameter roundfiber having an electrical resistivity of 0.00055 Ω-cm.

The average particle size of an electrically conductive filler can bewithin a range useful for imparting electrical conductivity to apolymer-based composition. For example, in certain embodiments, theparticle size of the one or more fillers can range from 0.25 μm to 250μm, in certain embodiments can range from 0.25 μm to 75 μm, and incertain embodiments can range from 0.25 μm to 60 μm. In certainembodiments, composition of the present disclosure can comprise KetjenBlack EC-600 JD (Akzo Nobel, Inc., Chicago, Ill.), an electricallyconductive carbon black characterized by an iodine absorption of1000-11500 mg/g (J0/84-5 test method), and a pore volume of 480-510cm³/100 gm (DBP absorption, KTM 81-3504). In certain embodiments, anelectrically conductive carbon black filler is Black Pearls 2000 (CabotCorporation, Boston, Mass.).

In certain embodiments, electrically conductive polymers can be used toimpart or modify the electrical conductivity of compositions of thepresent disclosure. Polymers having sulfur atoms incorporated intoaromatic groups or adjacent to double bonds, such as in polyphenylenesulfide, and polythiophene, are known to be electrically conductive.Other electrically conductive polymers include, for example,polypyrroles, polyaniline, poly(p-phenylene) vinylene, andpolyacetylene. In certain embodiments, the sulfur-containing polymersforming a base composition can be polysulfides and/or polythioethers. Assuch, the sulfur-containing polymers can comprise aromatic sulfur groupsand sulfur atoms adjacent to conjugated double bonds such asvinylcyclohexene-dimercaptodioxaoctane groups, to enhance the electricalconductivity of the compositions of the present disclosure.

Compositions of the present disclosure can comprise more than oneelectrically conductive filler and the more than one electricallyconductive filler can be of the same or different materials and/orshapes. For example, a sealant composition can comprise electricallyconductive Ni fibers, and electrically conductive Ni-coated graphite inthe form of powder, particles or flakes. The amount and type ofelectrically conductive filler can be selected to produce a sealantcomposition which, when cured, exhibits a sheet resistance (four-pointresistance) of less than 0.50 Ω/cm², and in certain embodiments, a sheetresistance less than 0.15 Ω/cm². The amount and type of filler can alsobe selected to provide effective EMI/RFI shielding over a frequencyrange of from 1 MHz to 18 GHz for an aperture sealed using a sealantcomposition of the present disclosure.

Galvanic corrosion of dissimilar metal surfaces and the conductivecompositions of the present disclosure can be minimized or prevented byadding corrosion inhibitors to the composition, and/or by selectingappropriate conductive fillers. In certain embodiments, corrosioninhibitors include strontium chromate, calcium chromate, magnesiumchromate, and combinations thereof. U.S. Pat. No. 5,284,888 and U.S.Pat. No. 5,270,364 disclose the use of aromatic triazoles to inhibitcorrosion of aluminum and steel surfaces. In certain embodiments, asacrificial oxygen scavenger such as Zn can be used as a corrosioninhibitor. In certain embodiments, the corrosion inhibitor can compriseless than 10% by weight of the total weight of the electricallyconductive composition. In certain embodiments, the corrosion inhibitorcan comprise an amount ranging from 2% by weight to 8% by weight of thetotal weight of the electrically conductive composition. Corrosionbetween dissimilar metal surfaces can also be minimized or prevented bythe selection of the type, amount, and properties of the conductivefillers comprising the composition.

In certain embodiments, a sulfur-containing polymer and/orsulfur-containing polymer adduct comprises from about 50 wt % to about90 wt % of a composition, from about 60 wt % to about 90 wt %, fromabout 70 wt % to about 90 wt %, and in certain embodiments, from about80 wt % to about 90 wt % of the composition, where wt % is based on thetotal dry solids weight of the composition.

A composition may also include any number of additives as desired.Examples of suitable additives include plasticizers, pigments,surfactants, adhesion promoters, thixotropic agents, fire retardants,masking agents, and accelerators (such as amines, including1,4-diazabicyclo[2.2.2]octane, DABCO®), and combinations of any of theforegoing. When used, the additives may be present in a composition inan amount ranging, for example, from about 0% to 60% by weight. Incertain embodiments, additives may be present in a composition in anamount ranging from about 25% to 60% by weight.

Uses

Compositions provided by the present disclosure may be used, forexample, in sealants, coatings, encapsulants, and potting compositions.A sealant includes a composition capable of producing a film that hasthe ability to resist operational conditions, such as moisture andtemperature, and at least partially block the transmission of materials,such as water, fuel, and other liquid and gases. A coating compositionincludes a covering that is applied to the surface of a substrate to,for example, improve the properties of the substrate such as theappearance, adhesion, wettability, corrosion resistance, wearresistance, fuel resistance, and/or abrasion resistance. A pottingcomposition includes a material useful in an electronic assembly toprovide resistance to shock and vibration and to exclude moisture andcorrosive agents. In certain embodiments, sealant compositions providedby the present disclosure are useful, e.g., as aerospace sealants and aslinings for fuel tanks.

In certain embodiments, compositions, such as sealants, may be providedas multi-pack compositions, such as two-pack compositions, wherein onepackage comprises one or more thiol-terminated polythioethers providedby the present disclosure and a second package comprises one or morepolyfunctional sulfur-containing epoxies provided by the presentdisclosure. Additives and/or other materials may be added to eitherpackage as desired or necessary. The two packages may be combined andmixed prior to use. In certain embodiments, the pot life of the one ormore mixed thiol-terminated polythioethers and epoxies is at least 30minutes, at least 1 hour, at least 2 hours, and in certain embodiments,more than 2 hours, where pot life refers to the period of time the mixedcomposition remains suitable for use as a sealant after mixing.

Compositions, including sealants, provided by the present disclosure maybe applied to any of a variety of substrates. Examples of substrates towhich a composition may be applied include metals such as titanium,stainless steel, and aluminum, any of which may be anodized, primed,organic-coated or chromate-coated; epoxy; urethane; graphite; fiberglasscomposite; Kevlar®; acrylics; and polycarbonates. In certainembodiments, compositions provided by the present disclosure may beapplied to a coating on a substrate, such as a polyurethane coating.

Compositions provided by the present disclosure may be applied directlyonto the surface of a substrate or over an underlayer by any suitablecoating process known to those of ordinary skill in the art.

Furthermore, methods are provided for sealing an aperture utilizing acomposition provided by the present disclosure. These methods comprise,for example, applying a composition provided by the present disclosureto a surface to seal an aperture, and curing the composition. In certainembodiments, a method for sealing an aperture comprises (a) applying asealant composition provided by the present disclosure to one or moresurfaces defining an aperture, (b) assembling the surfaces defining theaperture, and (c) curing the sealant, to provide a sealed aperture.

In certain embodiments, a composition may be cured under ambientconditions, where ambient conditions refers to a temperature from 20° C.to 25° C., and atmospheric humidity. In certain embodiments, acomposition may be cured under conditions encompassing a temperaturefrom a 0° C. to 100° C. and humidity from 0% relative humidity to 100%relative humidity. In certain embodiments, a composition may be cured ata higher temperature such as at least 30° C., at least 40° C., and incertain embodiments, at least 50° C. In certain embodiments, acomposition may be cured at room temperature, e.g., 25° C. In certainembodiments, a composition may be cured upon exposure to actinicradiation, such as ultraviolet radiation. As will also be appreciated,the methods may be used to seal apertures on aerospace vehiclesincluding aircraft and aerospace vehicles.

In certain embodiments, the composition achieves a tack-free cure inless than about 2 hours, less than about 4 hours, less than about 6hours, less than about 8 hours, and in certain embodiments, less thanabout 10 hours, at a temperature of less than about 200° F.

The time to form a viable seal using curable compositions of the presentdisclosure can depend on several factors as can be appreciated by thoseskilled in the art, and as defined by the requirements of applicablestandards and specifications. In general, curable compositions of thepresent disclosure develop adhesion strength within 24 hours to 30hours, and 90% of full adhesion strength develops from 2 days to 3 days,following mixing and application to a surface. In general, full adhesionstrength as well as other properties of cured compositions of thepresent disclosure becomes fully developed within 7 days followingmixing and application of a curable composition to a surface.

Cured compositions disclosed herein, such as cured sealants, exhibitproperties acceptable for use in aerospace applications. In general, itis desirable that sealants used in aviation and aerospace applicationsexhibit the following properties: peel strength greater than 20 poundsper linear inch (pli) on Aerospace Material Specification (AMS) 3265Bsubstrates determined under dry conditions, following immersion in JRFfor 7 days, and following immersion in a solution of 3% NaCl accordingto AMS 3265B test specifications; tensile strength between 300 poundsper square inch (psi) and 400 psi; tear strength greater than 50 poundsper linear inch (pli); elongation between 250% and 300%; and hardnessgreater than 40 Durometer A. These and other cured sealant propertiesappropriate for aviation and aerospace applications are disclosed in AMS3265B, the entirety of which is incorporated herein by reference. It isalso desirable that, when cured, compositions of the present disclosureused in aviation and aircraft applications exhibit a percent volumeswell not greater than 25% following immersion for one week at 60° C.(140° F.) and ambient pressure in JRF type 1. Other properties, ranges,and/or thresholds may be appropriate for other sealant applications.

In certain embodiments, therefore, compositions provided by the presentdisclosure are fuel-resistant. As used herein, the term “fuel resistant”means that a composition, when applied to a substrate and cured, canprovide a cured product, such as a sealant, that exhibits a percentvolume swell of not greater than 40%, in some cases not greater than25%, in some cases not greater than 20%, in yet other cases not morethan 10%, after immersion for one week at 140° F. (60° C.) and ambientpressure in Jet Reference Fluid (JRF) Type I according to methodssimilar to those described in ASTM D792 (American Society for Testingand Materials) or AMS 3269 (Aerospace Material Specification). JetReference Fluid JRF Type I, as employed for determination of fuelresistance, has the following composition: toluene: 28±1% by volume;cyclohexane (technical): 34±1% by volume; isooctane: 38±1% by volume;and tertiary dibutyl disulfide: 1±0.005% by volume (see AMS 2629, issuedJul. 1, 1989, §3.1.1 etc., available from SAE (Society of AutomotiveEngineers)).

In certain embodiments, compositions provided herein provide a curedproduct, such as a sealant, exhibiting a tensile elongation of at least100% and a tensile strength of at least 400 psi when measured inaccordance with the procedure described in AMS 3279, §3.3.17.1, testprocedure AS5127/1, §7.7.

In certain embodiments, compositions provide a cured product, such as asealant, that exhibits a lap shear strength of greater than 200 psi,such as at least 220 psi, at least 250 psi, and, in some cases, at least400 psi, when measured according to the procedure described in SAEAS5127/1 paragraph 7.8.

In certain embodiments, a cured sealant comprising a compositionprovided by the present disclosure meets or exceeds the requirements foraerospace sealants as set forth in AMS 3277.

Apertures, including apertures of aerospace vehicles, sealed withcompositions provided by the present disclosure are also disclosed.

In certain embodiments, an electrically conductive sealant compositionprovided by the present disclosure exhibits the following propertiesmeasured at room temperature following exposure at 500° F. for 24 hours:a surface resistivity of less than 1 ohms/square, a tensile strengthgreater than 200 psi, an elongation greater than 100%, and a cohesivefailure of 100% measured according to MIL-C-27725.

In certain embodiments, a cured sealant provided by the presentdisclosure exhibits the following properties when cured for 2 days atroom temperature, 1 day at 140° F., and 1 day at 200° F.: a dry hardnessof 49, a tensile strength of 428 psi, and an elongation of 266%; andafter 7 days in JRF, a hardness of 36, a tensile strength of 312 psi,and an elongation of 247%.

In certain embodiments, compositions provided by the present disclosureexhibit a Shore A hardness (7-day cure) greater than 10, greater than20, greater than 30, and in certain embodiments, greater than 40; atensile strength greater than 10 psi, greater than 100 psi, greater than200 psi, and in certain embodiments, greater than 500 psi; an elongationgreater than 100%, greater than 200%, greater than 500%, and in certainembodiments, greater than 1,000%; and a swell following exposure to JRF(7 days) less than 20%.

EXAMPLES

Embodiments provided by the present disclosure are further illustratedby reference to the following examples, which describe the synthesis,properties, and uses of certain sulfur-containing polymers, Michaelacceptor adducts, and compositions comprising sulfur-containingpolymers, Michael acceptor adducts, and Michael acceptors. It will beapparent to those skilled in the art that many modifications, both tomaterials, and methods, may be practiced without departing from thescope of the disclosure.

Example 1 Polythioether Cured with Monomeric Divinyl Sulfone

To prepare Resin Mixture A, thiol-terminated polythioethers of the typedescribed in U.S. Pat. No. 6,172,179, average thiol functionality:2.05-2.95, commercially available from PRC-Desoto International, Inc.,Sylmar, Calif., HB-40 plasticizer (Solutia Inc.), DABCO® 33LV(Huntsman), Winnofil® SPM (Solvay), Sipernat® D13 (Evonik) and tung oil(Alnor Oil Company, Inc.) were added to a Max 300 (FlackTek) jar in theorder and amounts listed in Table 1. The materials were mixed with a DAC600.1 FVZ mixer (FlackTek) for 45 seconds. Vinyl sulfone (Aldrich) (4.99g) was then add to Resin Mixture A and mixed for 1 minute. The mixturewas immediately poured onto polyethylene sheets and pressed out flat toform a ⅛″ sheets. Samples were cured for two weeks at room temperature.The sheet material was then tested for hardness, tensile strength,elongation, and fluid resistance. The results are provided in Table 2.

TABLE 1 Components of Resin Mixture A. Resin Mixture A Material Amount(g) Polythioethers* 140.05 HB-40 1.18 DABCO ® 33LV 1 . . . 58 Winnofil ®SPM 43.08 Sipernat ® D13 9.11 * *Thiol-terminated polythioethers of thetype described in U.S. Pat. No. 6,172,179, average thiol functionality:2.05-2.95, commercially available from PRC-Desoto International, Inc.,Sylmar, CA.

TABLE 2 Tests properties, methods and results. Description Test ResultDurometer ASTM D2240 53 (Shore A) Elongation ASTM D412 390% TensileStrength ASTM D412 3006 Kpas Swell, distilled SAE AS5271/1 7.4  8.3%water Swell, 3% NaCl SAE AS5271/1 7.4  3% Swell, JRF SAE AS5271/1 7.416.7% 

Example 2 Polysulfide Polymer Cured with Monomeric Divinyl Sulfone

Mixing was performed in a 60-g plastic container with a lid. Divinylsulfone (1.22 g), triethylenediamine (0.17 g) and Thiokol LP-32 (33.01g, a liquid polysulfide polymer available from Toray Fine Chemicals)were added to the 60-g container. The container was placed in a mixer(DAC 600 FVZ) and mixed for 60 seconds at 2,300 rpm. The mixed materialwas cured inside the plastic container for 7 days at room temperature.After 7 days, the hardness of the cured material was 14 Shore A,measured according to ASTM D 2240.

Example 3 Polythioether Cured with Monomeric Divinyl Sulfone

Divinyl sulfone (3.05 g), triethylenediamine (0.39 g) and Permapol®P3.1E (74.7 g, a thiol-terminated polythioether polymer available fromPRC-Desoto International, Inc., Sylmar, Calif.) were added to a plasticcontainer. The container was placed in a mixer (DAC 600 FVZ) and mixedfor 60 seconds at 2,300 rpm.

A portion of the mixed material was cured inside the plastic containerfor 7 days at room temperature. After 7 days, the hardness of the curedmaterial was 42 Shore A, measured according to ASTM D 2240.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 696 psi and an elongation of 933%. The tensilestrength and elongation were measured according to ASTM D412.

Example 4 Polythioether Cured with Divinyl Sulfone

Divinyl sulfone (3.05 g), triethylenediamine (0.62 g), Permapol® P3.1E(74.70 g, a thiol-terminated polythioether polymer available fromPRC-Desoto International, Inc., Sylmar, Calif.), and calcium carbonate(48.50 g) were added to a 100-gram plastic container. The container wasplaced in a mixer (DAC 600 FVZ) and mixed for 60 seconds at 2,300 rpm.

A portion of the mixed material was cured inside the plastic containerfor 7 days at room temperature. After 7 days, the hardness of curedmaterial was 25 Shore A, measured according to ASTM D 2240.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 546 psi and an elongation of 1,077%. The tensilestrength and elongation were measured according to ASTM D412.

Example 5 Synthesis of Divinyl Sulfone-Terminated Polythioether Adduct

In a 300 mL, 3-necked, round bottom flask fitted with a mechanicalstirrer, thiol-terminated polythioether polymer Permapol® P3.1E (149.40g, available from PRC-Desoto International, Inc., Sylmar, Calif.),divinyl sulfone (12.18 g), and triethylenediamine (0.81 g) were added atroom temperature. The mixture was stirred for 10 minutes, resulting avinyl sulfone-terminated polythioether adduct that had a viscosity of309.0 poise. The viscosity was measured by CAP2000 viscometer withspindle #6, 50 RPM.

Example 6 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polysulfide Polymer

Mixing was performed in a 60-gram plastic container with lid. The adductfrom Example 5 (9.27 g) and Thiokol LP-980 (5.90 g, a liquid polysulfidepolymer, available from Toray Fine Chemicals) were added to the 60-gramcontainer. The container was placed in a mixer (DAC 600 FVZ) and mixedfor 60 seconds at 2,300 rpm. The mixed material was cured inside theplastic container for 7 days at room temperature. After 7 days, hardnessof cured material was 11 Shore A and volume swell percentage in jetreference fluid type I (JRF Type I) of cured material was 19.20%.Hardness and volume swell percentage in jet reference fluid type I (JRFType I) were measured according to ASTM D 2240 and SAE AS5127/1 Section7.4, respectively.

Example 7 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polysulfide Polymer

Mixing was performed in a 60-g plastic container with lid. The adductfrom Example 5 (9.27 g) and Thiokol LP-32 (9.17 g, a liquid polysulfidepolymer, available from Toray Fine Chemicals) were added to the 60-gcontainer. The container was placed in a mixer (DAC 600 FVZ) and mixedfor 60 seconds at 2,300 rpm. The mixed material was cured inside theplastic container for 7 days at room temperature. After 7 days, hardnessof cured material is 24 Shore A and volume swell percentage in jetreference fluid type I (JRF Type I) of cured material is 18.81%.Hardness and volume swell percentage in jet reference fluid type I (JRFType I) were measured according to ASTM D 2240 and SAE AS5127/1 Section7.4, respectively.

Example 8 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polysulfide Polymer

Mixing was performed in a 60-gm plastic container with lid. The adductfrom Example 5 (9.27 g) and Thiokol LP-12 (9.17 g, a liquid polysulfidepolymer, available from Toray Fine Chemicals) were added to the 60-gmcontainer. The container was placed in a mixer (DAC 600 FVZ) and mixedfor 60 seconds at 2,300 rpm. The mixed material was cured inside theplastic container for 7 days at room temperature. After 7 days, hardnessof cured material is 25 Shore A and volume swell percentage in jetreference fluid type I (JRF Type I) of cured material is 19.41%.Hardness and volume swell percentage in jet reference fluid type I (JRFType I) were measured according to ASTM D 2240 and SAE AS5127/1 Section7.4, respectively.

Example 9 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polysulfide Polymer

Mixing was performed in a plastic container with lid. The adduct fromExample 5 (74.13 g) and Thioplast® G4 (19.12 g, a liquid polysulfidepolymer, available from Akzo Nobel) were added to the container. Thecontainer was placed in a mixer (DAC 600 FVZ) and mixed for 60 secondsat 2,300 rpm. A portion of the mixed material was cured inside theplastic container for 7 days at room temperature. After 7 days, hardnessof cured material is 25 Shore A and volume swell percentage in jetreference fluid type I (JRF Type I) of cured material is 18.70%.Hardness and volume swell percentage in jet reference fluid type I (JRFType I) were measured according to ASTM D 2240 and SAE AS5127/1 Section7.4, respectively.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 92 psi and an elongation of 181%. The tensilestrength and elongation were measured according to ASTM D412.

Example 10 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polysulfide Polymer

The mixing was performed in a plastic container with lid. The adductfrom Example 5 (74.13 g) and Thioplast® G21 (48.80 g, a liquidpolysulfide polymer, available from Akzo Nobel) were added to thecontainer. The container was placed in a mixer (DAC 600 FVZ) and mixedfor 60 seconds at 2,300 rpm. A portion of the mixed material was curedinside the plastic container for 7 days at room temperature. After 7days, hardness of cured material is 32 Shore A and volume swellpercentage in jet reference fluid type I (JRF Type I) of cured materialis 18.48%. Hardness and volume swell percentage in jet reference fluidtype I (JRF Type I) were measured according to ASTM D 2240 and SAEAS5127/1 Section 7.4, respectively.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 88 psi and an elongation of 107%. The tensilestrength and elongation were measured according to ASTM D412.

Example 11 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polysulfide Polymer

The mixing was performed in a plastic container with lid. The adductfrom Example 5 (55.60 g) and Thiokol LP-2 (57.48 g, a liquid polysulfidepolymer, available from Toray Fine Chemicals) were added to thecontainer. The container was placed in a mixer (DAC 600 FVZ) and mixedfor 60 seconds at 2,300 rpm. A portion of the mixed material was curedinside the plastic container for 7 days at room temperature. After 7days, hardness of cured material is 33 Shore A and volume swellpercentage in jet reference fluid type I (JRF Type I) of cured materialis 18.06%. Hardness and volume swell percentage in jet reference fluidtype I (JRF Type I) were measured according to ASTM D 2240 and SAEAS5127/1 Section 7.4, respectively.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 108 psi and an elongation of 113%. The tensilestrength and elongation were measured according to ASTM D412.

Example 12 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polythioether Polymer

The mixing was performed in a plastic container with lid. The adductfrom Example 5 (32.56 g) and Permapol® P3.1E (29.96 g, athiol-terminated polythioether polymer available from PRC-DesotoInternational Inc., Sylmar, Calif.), and triethylenediamine (0.31 g)were added to the container. The container was placed in a mixer (DAC600 FVZ) and mixed for 60 seconds at 2,300 rpm. A portion of the mixedmaterial was cured inside the plastic container for 7 days at roomtemperature. After 7 days, hardness of cured material is 31 Shore A.Hardness was measured according to ASTM D 2240.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 446 psi and an elongation of 504%. The tensilestrength and elongation were measured according to ASTM D412.

Example 13 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polythioether Polymer

A sealant was produced according to the composition shown in Table 1.

TABLE 1 Formulation of Example 13. Charge Composition weight, g Example5 adduct 34.17 Permapol ® P3.1E 29.96 Carbon Black 20.00Triethylenediamine 0.32

The mixing was performed in a 100-gram plastic container with lid. Theadduct from Example 5 (34.17 g), Permapol® P3. E (29.96 g, athiol-terminated polythioether polymer, available from PRC-DesotoInternational Inc., Sylmar, Calif.), carbon black (20.00 g), andtriethylenediamine (0.32 g) were added to the 100-gram container. Thecontainer was placed in a mixer (DAC 600 FVZ) and mixed for 60 secondsat 2,300 rpm. A portion of the mixed material was cured inside theplastic container for 7 days at room temperature. After 7-day cure,hardness of cured material is 43 Shore A, measured according to ASTM D2240.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 1810 psi and an elongation of 950%. The tensilestrength and elongation were measured according to ASTM D412.

Example 14 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polythioether Polymer, Low Density

A sealant was produced according to the composition shown in Table 2:

TABLE 2 Formulation of Example 14. Composition Charge weight, g Example5 adduct 34.17 Permapol ® P3.1E 29.96 Carbon Black 7.20Triethylenediamine 0.32 Dualite ® E135-040D 7.20

The mixing was performed in a 100-gram plastic container with lid. Theadduct from Example 5 (34.17 g), Permapol® P3. E (29.96 g, athiol-terminated polythioether polymer, available from PRC-DesotoInternational Inc., Sylmar, Calif.), carbon black (7.20 g),triethylenediamine (0.32 g) and Dualite® E135-040D (7.20 g, availablefrom Henkel) were added to the 100-gram container. The container wasplaced in a mixer (DAC 600 FVZ) and mixed for 60 seconds at 2,300 rpm. Aportion of the mixed material was cured inside the plastic container for7 days at room temperature. After 7 days, hardness of cured material is35 Shore A, measured according to ASTM D 2240.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 252 psi and an elongation of 772%. The tensilestrength and elongation were measured according to ASTM D412. Theestimated specific gravity was 0.706.

Example 15 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polythioether and Epoxy Blend

The mixing was performed in a 60-gm plastic container with lid. Theadduct from Example 5 (16.28 g) and Permapol® P3.1E (29.96 g, athiol-terminated polythioether polymer, available from PRC-DesotoInternational Inc., Sylmar, Calif.), triethylenediamine (0.23 g), andNovalac® DEN™ 431 (1.75 g, an epoxy resin available from Dow Chemical,Midland, Mich.) were added to the 60-gram container. The container wasplaced in a speed mixer (DAC 600 FVZ) and mixed for 60 seconds for 2,300rpm. A portion of the mixed material was cured inside the plasticcontainer for 7 days at room temperature. After 7-day cure, hardness ofcured material is 35 Shore A, measured according to ASTM D 2240.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 228 psi and an elongation of 276%. The tensilestrength and elongation were measured according to ASTM D412.

Example 16 Polythioether Michael Acceptor Adduct Cured with aThiol-Terminated Polythioether and Isocyanate Blend

The mixing was performed in a 60-gram plastic container with lid. Theadduct from Example 5 (33.04 g), Permapol® P3.1E (38.05 g, athiol-terminated polythioether polymer, available from PRC-DesotoInternational Inc., Sylmar, Calif.), and an isocyanate-terminatedprepolymer (5.0 g, Example 5 of U.S. application Ser. No. 13/050,988).The container was placed in a speed mixer (DAC 600 FVZ) and mixed for 60seconds for 2,300 rpm. A portion of the mixed material was allowed tocure inside the plastic container for 7 days at room temperature. After7-day cure, hardness of cured material was 35 Shore A, measuredaccording to ASTM D 2240.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet has atensile strength of 309 psi and elongation of 576%. The tensile strengthand elongation were measured per ASTM D412.

Example 17 Summary Results

The properties of the cured compositions presented in Examples 1-16 aresummarized in Table 3. In general, for aerospace sealant applications,it is desirable that a cured composition exhibit a hardness greater thanabout 10 Shore A, a tensile strength greater than about 10 psi, anelongation greater than about 100%, and a JRF swell less than about 20volume %. Note that Examples 13 and 14 include filler, whereas the othercompositions contain polymer only. For compositions containing polymeronly, it is generally desirable that the composition exhibit a tensilestrength greater than 80 psi and elongation greater than 100%.

TABLE 3 Summary of composition properties. Hard- ness Shore A TensileJRF Curing 7-day Strength Elongation swell Example Polymer Agent cure(psi) (%) (vol %) 1 PTE* DVS**  —^(†) — — — 2 PTE DVS 14 — — — 3 PTE DVS42 696 933 — 4 PTE DVS 25 546 1077  — 5 — — — 6 PTE PS^(§) 11 — — 19.2Adduct LP-980 7 PTE PS 24 — — 18.8 Adduct LP-32 8 PTE PS 25 — — 19.4Adduct LP-12 9 PTE PS 25  92 181 18.7 Adduct G4 10 PTE PS 32  88 10718.5 Adduct G21 11 PTE PS 33 108 113 18.1 Adduct LP-2 12 PTE PTE 31 446504 — Adduct 13 PTE PTE 43 1810  950 — Adduct 14 PTE PTE (low 35 252 772— Adduct density) 15 PTE PTE 35 228 276 — Adduct epoxy blend 16 PTE PTE35 309 576 — Adduct isocyanate blend *Polythioether. **Divinyl sulfone.^(§)Polysulfide. ^(†)Not measured.

Example 18 Polythioether Michael Acceptor Adduct Cured with a Diamine

The divinyl sulfone-terminated polythioether adduct from Example 5(83.99 g), isophorone diamine (4.26 g), Cab-O—Sil® M5 (3.68 g) andtriethylenediamine (0.69 g) were added to a plastic container. Thecontainer was placed in a mixer (DAC 600 FVZ) and the contents mixed for60 seconds at 2,300 rpm. A portion of the mixed material was curedinside the plastic container for 7 days at room temperature. After 7days, the hardness of cured material measured according to ASTM D 2240was 24 Shore A.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 562 psi and an elongation of 1170%. The tensilestrength and elongation were measured according to ASTM D412.

Example 19 Polythioether Michael Acceptor Adduct Cured with a Diamine

The divinyl sulfone-terminated polythioether adduct from Example 5(83.99 g), isophorone diamine (4.26 g) and Cab-O—Sil M5 (3.68 g) wereadded to a plastic container. The container was placed in a mixer (DAC600 FVZ) and the contents mixed for 60 seconds at 2,300 rpm. A portionof the mixed material was cured inside the plastic container for 7 daysat room temperature. After 7 days, the hardness of cured materialmeasured according to ASTM D 2240 was 20 Shore A.

A second portion of the mixed material was poured onto a 12″×18″×¼″ flatglass substrate and pressed to form a uniform ⅛″-thick sheet. The sheetwas cured for 7 days at ambient conditions. The cured sheet had atensile strength of 420 psi and an elongation of 1209%. The tensilestrength and elongation were measured according to ASTM D412.

Example 20 Polythioether Michael Acceptor Adduct Cured with a BlockedDiamine

The adduct from Example 5 (16.80 g), Vestamin® A 139 (1.39 g, availablefrom Evonik) and triethylenediamine (0.27 g) were added to a plasticcontainer. The container was placed in a mixer (DAC 600 FVZ) and mixedfor 60 seconds at 2,300 rpm. A portion of the mixed material was curedin the plastic container for 5 weeks at ambient conditions. After 5weeks, the mixed material cured, forming a solid elastomer.

Finally, it should be noted that there are alternative ways ofimplementing the embodiments disclosed herein. Accordingly, the presentembodiments are to be considered as illustrative and not restrictive.Furthermore, the claims are not to be limited to the details givenherein, and are entitled their full scope and equivalents thereof.

What is claimed is:
 1. A polysulfide adduct comprising at least twoterminal Michael acceptor groups.
 2. The polysulfide adduct of claim 1,wherein the Michael acceptor groups comprise the structure of Formula(2):—CH₂—C(R⁴)₂—S(O)₂—C(R⁴)₂═CH₂  (2) wherein each R⁴ is independentlyselected from hydrogen and C₁₋₃ alkyl.
 3. The polysulfide adduct ofclaim 1, wherein the polysulfide adduct comprises the reaction productsof reactants comprising: (a) a thiol-terminated polysulfide polymer; and(b) a compound having a Michael acceptor group and a group that isreactive with a thiol group, wherein the Michael acceptor group has thestructure of Formula (2):—CH₂—C(R⁴)₂—S(O)₂—C(R⁴)₂═CH₂  (2) wherein each R⁴ is independentlyselected from hydrogen and C₁₋₃ alkyl.
 4. The polysulfide adduct ofclaim 3, wherein the thiol-terminated polysulfide polymer comprises: (a)from 90 mole percent to 25 mole percent of a thiol-terminatedpolysulfide polymer of the Formula HS(RSS)_(m)R—SH; and (b) from 10 molepercent to 75 mole percent of a diethyl formal thiol-terminatedpolysulfide polymer of the Formula HS(RSS)_(n)R—SH, wherein, R isselected from —C₂H₄—O—CH₂—O—C₂H₄—, C₂₋₁2 alkanediyl, a C₄₋₂₀ thioether,a C₄₋₂₀ alkyl ether comprising one oxygen atom, a C₄₋₂₀ alkyl ethercomprising 2 to 4 oxygen atoms in which each of the oxygen atoms isseparated from another oxygen atom by at least 2 carbon atoms, C₆₋₁₂alicyclic, an aromatic lower alkyl; and m and n are selected to providean average molecular weight from 1,000 Daltons to 4,000 Daltons.
 5. Thepolysulfide adduct of claim 4, wherein R is selected from —CH₂—CH₂—,—C₂H₄—O—C₂H₄—, —C₂H₄—S—C₂H₄—, —C₂H₄—O—C₂H₄—O—C₂H₄—, and —CH₂—C₆H₄—CH₂—.6. The polysulfide adduct of claim 3, wherein the compound having aMichael acceptor group and a group that is reactive with a thiol groupcomprises divinyl sulfone.
 7. A composition comprising: (a) thepolysulfide adduct of claim 1; and (b) a compound having at least twoMichael acceptor groups, wherein the compound having at least twoMichael acceptor groups is characterized by a molecular weight less than400 Daltons.
 8. The composition of claim 7, comprising a polyepoxy. 9.The composition of claim 7, comprising a polyisocyanate comprisingisocyanate groups that are reactive with thiol groups and that are lessreactive with Michael acceptor groups.
 10. The composition of claim 7,comprising a polythioether polymer comprising at least two terminalgroups reactive with Michael acceptor groups.
 11. A compositioncomprising: (a) the polysulfide adduct of claim 1; and (b) a curingagent comprising at least two terminal groups that are reactive withMichael acceptor groups.
 12. The composition of claim 11, wherein thecuring agent is selected from a sulfur-containing polymer comprising atleast two terminal groups reactive with Michael acceptor groups, amonomeric thiol, a polythiol, a polyamine, a blocked amine, and acombination of any of the foregoing.
 13. The composition of claim 11,wherein the curing agent comprises a sulfur-containing polymercomprising at least two terminal groups reactive with Michael acceptorgroups.
 14. The composition of claim 13, wherein the sulfur-containingpolymer comprises a thiol-terminated polysulfide.
 15. The composition ofclaim 14, wherein the thiol-terminated polysulfide comprises athiol-terminated polysulfide polymer comprising: (a) from 90 molepercent to 25 mole percent of a thiol-terminated polysulfide polymer ofthe Formula HS(RSS)_(m)R—SH; and (b) from 10 mole percent to 75 molepercent of a diethyl formal thiol-terminated polysulfide polymer of theFormula HS(RSS)_(n)R—SH, wherein, R is selected from—C₂H₄—O—CH₂—O—C₂H₄—, C₂₋₁2 alkanediyl, a C₄₋₂₀ thioether, a C₄₋₂₀ alkylether comprising one oxygen atom, a C₄₋₂₀ alkyl ether comprising 2 to 4oxygen atoms in which each of the oxygen atoms is separated from anotheroxygen atom by at least 2 carbon atoms, C₆₋₁₂ alicyclic, an aromaticlower alkyl; and m and n are selected to provide an average molecularweight from 1,000 Daltons to 4,000 Daltons.
 16. The composition of claim13, wherein the sulfur-containing polymer comprises a polythioetherpolymer.
 17. The composition of claim 11, comprising a polyepoxy. 18.The composition of claim 11, comprising a polyisocyanate comprisingisocyanate groups that are reactive with thiol groups and that are lessreactive with Michael acceptor groups.
 19. The composition of claim 11,comprising a polythioether adduct, wherein the polythioether adductcomprises at least two terminal Michael acceptor groups.
 20. Acomposition comprising: (a) a sulfur-containing adduct containing atleast two Michael acceptor groups, wherein the sulfur-containing adductcomprises the polysulfide adduct of claim 1; (b) a sulfur-containingpolymer comprising at least two terminal groups reactive with Michaelacceptor groups; and (c) a monomeric compound having at least twoMichael acceptor groups.
 21. A hydroxyl-terminated sulfur-containingadduct comprising the reaction products of reactants comprising: (a) asulfur-containing Michael acceptor adduct comprising at least twoterminal Michael acceptor groups, wherein the sulfur-containing Michaelacceptor adduct comprises the polysulfide adduct of claim 1; and (b) acompound having a hydroxyl group and a group that is reactive with theterminal groups of the sulfur-containing Michael acceptor adduct.
 22. Acomposition comprising: (a) the hydroxyl-terminated sulfur-containingadduct of claim 21; and (b) a polyisocyanate curing agent.
 23. Anamine-terminated sulfur-containing adduct comprising the reactionproducts of reactants comprising: (a) a sulfur-containing Michaelacceptor adduct comprising at least two terminal Michael acceptorgroups, wherein the sulfur-containing Michael acceptor adduct comprisesthe polysulfide adduct of claim 1; and (b) a compound having a aminegroup and a group that is reactive with the terminal groups of thesulfur-containing Michael acceptor adduct.
 24. A composition comprising:(a) the amine-terminated sulfur-containing adduct of claim 23; and (b) apolyisocyanate curing agent.